Class 84 Thursday, 6/7/18

Warm-Up :

The ability of the observer on the right to see the penny depends on whether the penny is wet or dry.

1.  When can he see the penny?

2.  Explain why.

 Today:   

  • Quiz

  • To get credit for your instrument, email me a picture of all of your group members with your string instrument.

  • Make sure that you have the exam review materials (see yesterday, below)

  • Instrument work time.  Add bridges, nuts, strings.  Shim where necessary.

    • How to use the sheet sander (with earmuffs, in Mr. Horne's woodworking shop)

  • Doppler challenge 20 minutes from the end of class. 

Online Textbook Reading: 

Homework:  Prepare for final exam

Class 83.5 Wednesday, 6/6/18

Warm-Up :

1.  What is the object in the picture?

2.  Why can't the sky be seen throuhout the entire picture?

 Today:   

Online Textbook Reading: 

Homework: 

Class 83 Tuesday, 6/5/18

Warm-Up :Warm-Up :   Contemplate this -- the speed of light in a vacuum is always constant, relative to any observer.

Now consider the following situation.  Fred is conducting a laser experiment on a very, very, very fast train.  He attaches a mirror to the roof of the train car and shines a quick pulse of laser light directly upward at the mirror.  Hank is standing still outside the train.  The train car is made of glass, so Hank can see the whole thing.

The pulse of laser light goes up, reflects off of the mirror, and then goes back down to the floor.  There's enough dust in the air to make the laser pulse visible.

1)  If Fred and Hank were to draw the laser's "flight path" (as each of them sees it), what would each of them draw?

2)  Who would see light travel a greater distance?

3)  Assuming that Hank and Fred see light traveling the same speed, who sees it travel for the longest amount of time?

 Today:   

Online Textbook Reading: 

Homework: 

Class 82.5 Monday, 6/4/18

Warm-Up :Warm-Up :  

1.  Show how the rays of light will refract as they pass into and out of the water-filled glass vessel in Figure A.

2.  Show how light rayswill reflect when they hit the curved mirror in figure E.

Today:   

Online Textbook Reading: 

Homework: 

Class 82 Friday, 5/30/18

Warm-Up :   None, due (indirectly) to copier malfunction.

Today:   

  • Work on instruments.  Attach necks.  Check-in before attaching your bridge.

Online Textbook Reading: 

Homework:  Review for the final (unless you are confident that you will be exempt).

Class 81.5 Thursday, 5/31/18

Warm-Up :  

If you're overlooking some water, trying to spear a fish (as shown in the drawing on the right), where should you aim your spear?  Why?

 

Today:   

  • Return quizzes

  • Work on instruments.  Attach necks.  Check-in before attaching your bridge.

Online Textbook Reading: 

Homework:  None

Class 81 Wednesday, 5/30/18

Warm-Up :  

What is the procedure for using Mr. Horne's belt sander safely?

Optional cleaning of the belt, and putting the stick away.

**Note:  make sure that the sanded surface of your peg box is completely planar.

Today:   

  • Quiz

  • Sand the stair steps off of your peg box (or have a trustworthy person do it for you) and glue it to your instrument's neck. 

Online Textbook Reading: 

Homework:  None

Class 80.5 Tuesday, 5/29/18

Warm-Up :  

The diagrams on the right show plans for a solar oven with reflectors.  How should one choose the angle of the reflectors?

Today:   

  • Wrap fret string

Online Textbook Reading: 

Homework:  Quiz tomorrow.

Class 80 Friday, 5/25/18

Warm-Up :   No warm-up.  Test Today.

Today:   

  • If you have time, continue work on your instrument.  Assemble your peg box.

Online Textbook Reading: 

Homework:  None

Class 79.5 Thursday, 5/24/18

Warm-Up :  

1. What were the loudest sounds ever (according to listverse)?

2. How is sound volume measured?

Source of sound (in air) Sound Pressure -- amplitude
(psi) 
Volume in Decibels, calculated by
20*LogP/Po
Po (threshold of hearing, in psi) Loudest Pressure divided by Quietest Audible Pressure
Shockwave (distorted sound waves > 1 atm; waveform valleys are clipped at zero pressure) 14.69543147 194.0956869 2.9E-09 5,067,390,163
Theoretical limit for undistorted sound at 1 atmosphere environmental pressure 14.69543147 194.0956869    
Stun grenades 2.900652647 180.0019545    
Simple open-ended thermoacoustic device[6] 1.830166788 176.0018534    
.30-06 rifle being fired 1 m to shooter's side 1.053662074 171.206067    
M1 Garand rifle being fired at 1 m 0.728498912 168.0006182    
Rocket launch equipment acoustic tests 0.580130529 166.0225545    
Jet engine at 30 m 0.091660624 149.9956962    
Threshold of pain 0.009166062 129.9956962    
Vuvuzela horn at 1 m 0.002900653 120.0019545    
Hearing damage (possible) 0.002900653 120.0019545    
Jet engine at 100 m 0.029006526 140.0019545    
Non-electric chainsaw at 1 m 0.000913706 109.9681656    
Jack hammer at 1 m 0.000290065 100.0019545    
Traffic on a busy roadway at 10 m 9.15156E-05 89.98194182    
Hearing damage (over long-term exposure, need not be continuous) 5.16316E-05 85.01035459    
Passenger car at 10 m 2.90065E-05 80.00195455    
EPA-identified maximum to protect against hearing loss and other disruptive effects from noise, such as sleep disturbance, stress, learning detriment, etc.   #NUM!    
Handheld electric mixer 5.51124E-06 65.57702656 Classroom Unit Ventilator  
TV (set at home level) at 1 m 2.90065E-06 60.00195455    
Normal conversation at 1 m 2.90065E-06 60.00195455    
Very calm room 9.19507E-08 30.02313979    
Light leaf rustling, calm breathing 9.16606E-09 9.995696197    
Auditory threshold at 1 kHz 2.90065E-09 0.001954545    

 

Today:   

  • Check/review homework Practice Quiz    Solutions

  • Get Practice Quiz.  We will have a similar quiz on Friday.  There will be no string instrument fret calculations on this quiz.

  • Work on instruments

    • Remove tape

    • Have me check your fingerboard.  It needs to be flat (sort of).

    • Mark bridge position, measure bridge-to-nut distance, and calculate fret positions

    • Mark fret positions on finger board

Online Textbook Reading:  17.4 -- Doppler Shift and Sonic Booms

Homework:  Practice quiz over waves and sound  Practice Quiz    Solutions

Class 79 Wednesday, 5/23/18

Warm-Up :  

This is the 100 pound fishing line that we will be using to make frets and low (C on a ukulele) strings. 

1.  How should you remove line from this coil?

2.  When you make your frets, you won't know how much fishing line you're going to need.  How should you deal with that ambiguity?

3.  When you are finished with the coil of line, how should you prepare it for storage?

4.  Please, never remove the __________.

Today:   

  • Check/review homework 17.4 Practice solutions

  • Get Practice Quiz.  We will have a similar quiz on Friday.  There will be no string instrument fret calculations on this quiz.

  • Begin making instruments

    • Assemble your box

    • Trim and attach neck

    • Add hardwood strip to fingerboard

    • Measure and mark frets

    • Create frets by wrapping 100 lb fishing line around the neck.

Online Textbook Reading:  17.4 -- Doppler Shift and Sonic Booms

Homework:  Practice quiz over waves and sound  Practice Quiz Solutions

Class 78.5 Monday, 5/21/18

Warm-Up :  

If you're standing next to a race track, what do you hear as the cars pass you?

a.  Their pitch changes from high to low.

b.  Their pitch changes from low to high.

c.  There is no change in pitch.

Today:   

  • The Electricity and Magnetism retake is ready.  Complete it during Flex, when you're ready. 

  • Doppler Effect Videos and Simulations

  •  

  • In Rhino, draw a correctly dimensioned rectangle representing your instrument top.  Working in top view, orient your rectangle with the long axis vertical on your screen. Add desired 2-D features such as holes. Upload your instrument top design (in Rhino) to this Google Drive Folder.  Name the file with your names.  Also save the file on your computer so that you can identify your instrument top later on.

  • Provide information about your instrument's neck dimensions by filling out this form.

Online Textbook Reading:  17.4 -- Doppler Shift and Sonic Booms

Homework: 

  • Design and upload your instrument top and share your instrument neck dimensions (see details above). 
  • Read section 17.4.   Complete the 17.4 Practice.  Check your answers and look at the solutions when necessary.
Class 78 Friday, 5/18/18

Warm-Up :  

1. How does a violin bow cause a string to vibrate at its resonant frequency?
2. How does rubbing your finger on the rim of a glass create sound?
3. What steps would one follow to break a glass with one's voice?  Would you like to try?

Today:   

  • The Electricity and Magnetism retake is ready.  Complete it during Flex, when you're ready. 

  • Finish Notes #2: Standing waves, harmonics, interference, music and string instruments. Filled-In Notes

  • In Rhino, draw a correctly dimensioned rectangle representing your instrument top.  Working in top view, orient your rectangle with the long axis vertical on your screen. Add desired 2-D features such as holes. Upload your instrument top design (in Rhino) to this Google Drive Folder.  Name the file with your names.  Also save the file on your computer so that you can identify your instrument top later on.

  • Provide information about your instrument's neck dimensions by filling out this form.

Links:

Online Textbook Reading:  16.9 -- Waves

Homework: 

Class 77.5 Thursday, 5/17/18

Warm-Up :  

1.  What is a Chladni plate

Today:   

  • We're going to make cigar box instruments (1 ≤ strings ≤ 4 ). 

    • This is the basic design.  

    • Choose (a) partner(s) and make selections regarding instrument details. Fill out this form.  If you don't fill out the form, your group and box may be chosen for you.

    • Steps in the project:  modify the the design (sound holes); assemble resonator, pegs and peg box; determine scale length and shape neck; attach neck to resonator; add frets or fret marks; attach bridge; tune; complete recordings, sound analysis, and Doppler challenge.

  • Check/review homework

  • Finish Notes #2: Standing waves, harmonics, interference, music and string instruments. Filled-In Notes

Links:

Online Textbook Reading:  16.9 -- Waves

Homework:  None

 

Class 77 Wednesday, 5/16/18

Warm-Up :  

1.  What does the word resonate mean?

2. Identify any nodes and/or antinodes in this video of the "volcano."

3.  Which harmonic is this?  Could there be other harmonics?

4.  Does the guy creating the wave have control over the wave's frequency? Explain.

5.  How is making these waves like breaking glass with your voice?

Today:   

Links:

Online Textbook Reading:  16.9 -- Waves

Homework: 

Class 76.5 Tuesday, 5/15/18

Warm-Up : 

1. How can we find the wavelength of the vibrating violin string?

2.  Is it really a wave?

3.  What's wrong with question number 1?

Today:   

Links:

Online Textbook Reading:  16.9 -- Waves

Homework: 

Class 76 Monday, 5/14/18

Warm-Up : 

1.  What is a sound?

2.  How do we perceive sounds?

3.  If a tree falls in the forest, and there is no one there to hear it, does it still make a sound?

Today:   

Links:

Online Textbook Reading:  16.9 -- Waves

Homework: 

Image result for lightning strike house hillClass 75.5 Friday, 5/11/18

Warm-Up : 

1.  If you see lightning strike a point 1 mile away, how long can you expect to wait before you hear thunder?

2.  In the cat gif below, what is the  approximate wave frequency in waves per second (a.k.a. hertz)?

3.  If the distance between wave crests (a.k.a. wavelength) is 4m, what is the wave speed?

Today:   

Online Textbook Reading:  16.9 -- Waves

Homework: 

  • None
Image result for cat bobbing in  waves gifClass 75 Thursday, 5/10/18

Warm-Up :  What's wrong with this cat gif?

Today:   

Online Textbook Reading:  16.9 -- Waves

Homework: 

  • None
Class 74.5 Wednesday, 5/9/18

Warm-Up : 

How does a gas engine (with no battery) get the electricity to fire its spark plug? Here's one way.

Today:   

  • Check/discuss homework

  • Build yourself some right hands and a coil?  You may use them on the quiz, as long as they are not labeled.  Arrows are okay.

  • Finish projects

Online Textbook Reading:  Chapters 22 and 23

Homework: 

  • Quiz tomorrow
Class 74 Monday, 5/8/18

Warm-Up : 

What's inside a hand generator?

Today:   

  • Check/review homework

  • Build yourself some right hands and a coil?  You may use them on the quiz, as long as they are not labeled.

  • Finish projects

  • Start practice quiz

Online Textbook Reading:  Chapters 22 and 23

Homework: 

  • Finish practice quiz.
  • Quiz on Thursday over electricity and magnetism
Class 73.25 Monday, 5/7/18

Warm-Up : 

If I have three identical A.C. electric drills...

1.  How can I use one of them to generate electrical current?

2.  How can I power one of the drills using the electric current generated by one of the other drills?

Today:   

  • Play with amplifier, pickups, hand generators, etc.

Tomorrow:   

  • Check/review homework

  • Finish projects

  • Start practice quiz

Online Textbook Reading:  Chapters 22 and 23

Homework: 

  • None
Class 73  Friday, 5/4/18

Warm-Up : 

The picture on the far right shows a transformer.  The picture on the near right shows a simplified transformer.  The two coils are not connect to one another.  There is a wire connecting one of these to your home.

1.  What does a transformer do?

2.  Transformers work with alternating current (A.C.).  If the left coil's current (shown in the diagram) is increasing at this moment, what is the direction of the current in the coil on the right?

3.  The purpose of these transformers is to "step down" the high voltage in the transmission lines to a lower voltage that enters your home.  Why do the transmission lines need to have such high voltage?

4.  Why are homes powered by A.C., rather than D.C.?

Today:   

  • Check/review homework

  • Make Pickups

Online Textbook Reading:  Chapters 22 and 23

Homework: 

Class 72.5  Thursday, 5/3/18

Warm-Up : 

When its switch is flipped, the ring launcher will launch a conductive ring upward.  A conductive ring with a slit in it will not work.

How does a ring launcher like this work?

Today:   

  • Check/review homework

  • Make Pickups tomorrow.

Online Textbook Reading:  Chapters 22 and 23

Homework: 

Class 72  Wednesday, 5/2/18

Warm-Up : 

1.  Will a magnet stick to copper?

2.  What will happen if we drop a magnet down a copper tube?

Today:   

Online Textbook Reading:  Chapters 22 and 23

Homework: 

Class 71.5  Tuesday, 5/1/18

Warm-Up : 

Based on the direction of current flow, in which direction are the speaker cone and voice coil being pushed by the permanent magnet?

Today:   

  • Return tests tomorrow.

  • Finish motors, speakers, buzzers.

  • Tomorrow -- pickups????

Online Textbook Reading:  Chapters 22 and 23

Homework: 

  • None
Class 71  Monday, 4/30/18

Warm-Up : 

How does a speaker work?  How is it different from a solenoid buzzer?  What's wrong with the caption "magnet attached to cone?"

Today:   

Online Textbook Reading:  Chapters 22 and 23

Homework: 

  • None
Class 70.5  Friday, 4/20/18

Warm-Up : 

The diagram on the right shows how a car horn works.

1.  Which color (red or black) represents a complete circuit?

2.  Where is the solenoid?

3.  What makes this louder than the buzzer you have been working on?

Today:   

Online Textbook Reading:  Chapters 22 and 23

Homework: 

  • None
Class 70  Thursday, 4/19/18

Warm-Up : 

Test today.  No Warm-up.

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current  Chapter 21.1 (resistors in series and parallel) and Chapter 21.3 (Kirchoff's rules)

Homework: 

  • None
Class 69.5  Wednesday, 4/18/18

Warm-Up :  An enameled wire containing a coil is positioned over a permanent magnet, as shown in the diagram on the right.

1.  If current begins to flow through the wire in the direction shown, in which direction will the resulting magnetic force cause the wire to rotate?  (Answer from the perspective of someone standing at the red end and looking toward the blue end.)

2.  Once the wire rotates 180º from its current position, will the direction of the force change?

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current  Chapter 21.1 (resistors in series and parallel) and Chapter 21.3 (Kirchoff's rules)

Homework: 

Class 69  Tuesday, 4/17/18

Warm-Up :  The first diagram on the right shows the right hand rule for the magnetic field B created by an electrical current I.

1. When the magnetic field B is aligned with a permanent bar magnet, do the arrows point toward the north pole of the magnet or the south pole of the magnet?

2. When the circuit on the far right is switched on, what will be the direction of the magnetic field?

3.  The picture on the right shows a solenoid.  What makes a solenoid a solenoid?

4.  If the solenoid in the picture were an equivalent permanent magnet, where would its north pole be situated?

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current  Chapter 21.1 (resistors in series and parallel) and Chapter 21.3 (Kirchoff's rules)

Homework: 

Class 68.5  Monday, 4/16/18

Warm-Up : 

1.  Do you see anything wrong with this diagram?

2.  How did the North Pole get its name?

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current  Chapter 21.1 (resistors in series and parallel) and Chapter 21.3 (Kirchoff's rules)

Homework: 

Class 68  Friday, 4/13/18

Warm-Up : Imagine a 110V home circuit that powers two light bulbs, a 100W bulb and a 60W bulb. 

1. Which bulb will burn brighter when they are both turned on?

2.  Through which bulb will more current flow?

3.  Which bulb has a higher resistance?

4.  Imagine a home circuit with just one 100W bulb.  Why does the bulb use more power than the wires that carry current to the bulb?

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current  Chapter 21.1 (resistors in series and parallel) and Chapter 21.3 (Kirchoff's rules)

Homework:   Kirchoff's Rules 21.3 Notes and practice  -- Complete everything before "kirchoff's rules practice #2".  Solutions

Class 67.75  Thursday, 4/12/18

Warm-Up : 

1. What do 3-way switches do?

2.  How does one wire 3-way switches?

Today:   

  •  Turn-in circuit lab.  Questions about the circuit lab?
  • Work on practice test -- doesn't include Kirchoff's Rules.  We will start KR tomorrow.

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current  Chapter 21.1 (resistors in series and parallel) and Chapter 21.4 (Kirchoff's rules)

Homework:   Practice Test:  Chapter 20-21 Solutions **This practice test does not include Kirchoff's Rules, which will also be on the actual test.

Class 67.5  Wednesday, 4/11/18

Warm-Up : 

1. At the rate of 16 cents per kilowatt-hour, how much does it cost to leave a 100W light bulb on for an entire year?

2.  Kilowatt-hour is a unit of _____.

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current  Chapter 21.1 (resistors in series and parallel) and Chapter 21.4 (Kirchoff's rules)

Homework:  None

Class 67.25  Tuesday, 4/10/18

Warm-Up : 

The graph shows data collected using the same light bulb at a variety of voltages.  The graph curves because light bulbs do not follow Ohm's Law.

1.  What is happening to the bulb's resistance as current increases?

2.  Why does the resistance of light bulbs change in this way?

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current

Homework:   Problem 2 from Ch21 Equivalent Resistance Challenge Solutions

Class 67  Monday, 4/9/18

Warm-Up : 

How can we estimate the average speed (in m/s) at which data travel to this computer over the internet?

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current

Homework:   Problem 1 from Ch21 Equivalent Resistance Challenge Solutions

Class 66.5  Friday, 4/6/18

Warm-Up : 

1.  Which types of light bulbs flicker?  Why?

2.  What is the difference between A.C. and D.C. electricity?

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current

Homework:    Practice: 20.3, 20.4, and 21.1  20.3Solutions   20.4Solutions   21.1Solutions

Class 66  Thursday, 4/5/18

Warm-Up :  The deceptively complicated case of the electrified pickle...

Why does an electrified pickle light up on one end?  Is it always the same end?

joule heating

Electric Arc

Arc lamp

Hyperphysics electric pickle info

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current

Homework:   Due on Monday -- Practice: 20.3, 20.4, and 21.1  20.3Solutions   20.4Solutions   21.1Solutions

Class 65.5  Wednesday, 4/4/18

Warm-Up : 

Can we put out a candle with a Van de Graaff generator?

 

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current

Homework/Deadlines:    20.2 -- Notes and Practice  Solutions

Class 65  Tuesday, 4/3/18

Warm-Up : 

Can we simulate the electric fence system on the right using the electronic dog collar below?Image result for sportdog electric shock dog collar electrodes

 

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current

Homework/Deadlines:    19.1 Practice  Answer Key  Practice: 20.1 -- but not numer 10 Answer Key

Class 64.5  Monday, 4/2/18

Warm-Up : 

1.  Using some rabbit fur, a rubber stick, and two isolated conductors, how can you positively charge one conductor and negatively charge the other?

2.  Once the conductors are charged, you insulate them and separate them from any other strong electric fields.  As you do this, what happens to the protons and the electrons in the two conductors?

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current

Homework/Deadlines:    None

Class 64  Friday, 3/30/18

Warm-Up : 

Test.  No warm-up

Today:   

  • Test

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current

Homework/Deadlines:    None

Image result for proton accelerating in an electric fieldClass 63.5  Thursday, 3/29/18

Warm-Up : 

Voltage : Potential Energy :: Electric Field : Force

1.  The analogy above holds true with regard to units.  If the units for electric field are N/C, what are the units* for voltage?

2.  Because of its relationship to potential energy, voltage is also referred to as electrical potential.  Given the units of voltage (from #1), how many Joules of PEE would be stored in stored in a 5C charge at 3V of  electrical potential?

3.  Spring PE:Spring Force :: Voltage: ______ ?

Today:   

Online Textbook Reading: Chapter 19.1 -- Electrical Potential (Voltage)     Chapter 20 -- Electric Current

Homework/Deadlines:    Test tomorrow

Image result for bird on a power lineClass 63  Wednesday, 3/28/18

Warm-Up : 

Why doesn't a bird on an uninsulated power line get shocked?

Today:   

Online Textbook Reading:  Chapter 20 -- Electric Current

Homework/Deadlines:    Electrostatics Practice Test (Mr Pennington's Old Test)  -- Answer Key

Class 62.5  Tuesday, 3/27/18

Warm-Up : 

1. What is a spark?

2. How does a plasma ball work?

Today:   

Online Textbook Reading:  Chapter 18.1-18.5

Homework/Deadlines:  Due on Thursday  Electrostatics Practice Test (Mr Pennington's Old Test)  -- Answer Key

Class 62  Monday, 3/26/18

Warm-Up :  Suppose the neutral conductor in diagram A is placed in the electric field shown in diagram B.

1.  How will the charges that are currently shown on the conductor rearrange themselves?  Assume that both positive and negative charges can move equally well.

2.  How will the electric field lines rearrange themselves?

Answer

Today:   

Online Textbook Reading:  Chapter 18.1-18.5

Homework/Deadlines: 

Class 61.5  Thursday, 3/22/18

Warm-Up : 

1.  In the diagram on the right, which charge is stronger?

2.  How can you determine the relative strengths of the charges in the diagram?

3.  True or False:  If you placed a proton on one of the lines in the diagram to the right, it would move in a path following the line.

Today:   

Online Textbook Reading:  Chapter 18.1-18.5

Homework/Deadlines: 

Class 61  Wednesday, 3/21/18

Warm-Up : 

We have a video showing Brody hovering across the 200 foot long hockey rink.  How can we determine the coefficient of friction of his hovercraft on ice?

Today:   

Online Textbook Reading:  Chapter 18.1-18.5

Homework/Deadlines: 

Class 60.5  Tuesday, 3/20/18

Warm-Up : 

Physics at the rink

Today:   

  • Coefficients of restitution -- hovercraft vs:  hovercraft, wall
  • Coefficient of drag
  • Leafblower thrust
  • Hero engine?
  • Conservation of Angular Momentum
  • Conservation of linear momentum

Online Textbook Reading:  Chapter 18.1-18.4

Homework/Deadlines:  Due on Wednesday 

Class 60  Monday, 3/19/18

Warm-Up : 

The electrophorus is charged by rubbing a cat(fur) against the top of an insulating plate (I).  Then the conducting plate (C) is placed on top of the insulating plate and is touched by the physicist.  Assuming that the cat fur has a strong affinity for positive charge...

1.  What is the charge of the plate after it is touched by the scientest? 

2.  Explain how the conducting plate becomes charged.

Today:   

Online Textbook Reading:  Chapter 18.1-18.4

Homework/Deadlines:   

Class 59.5  Friday, 3/16/18

Warm-Up : 

Figure B on the right shows the distribution of excess charge on an isolated positively charged conductor with an irregular shape. 

1.  Why does excess charge move to the outside surface of a conductor?

2.  In diagram B, it looks like positive charges moved to the outside of the conductor.  Why can't this happen?  What really happened?

3.  In diagram B, why aren't the charges evenly distributed around the perimeter of the object?  Why are they closest at the pointiest parts and farthest at the flattest parts?

Today:   

Online Textbook Reading:  Chapter 18.1-18.2

Homework/Deadlines:  Chapter 18.2 Practice -- Solutions

Class 59  Thursday, 3/15/18

Warm-Up : 

Suppose we have a pith ball.  In this case, the pith ball is a foam ball with a metallic coating.  What happens if you touch the VDG and then reach out to  touch a hanging pith ball?

Today:   

Online Textbook Reading:  Chapter 18.1-18.2

Homework/Deadlines: 

Class 58  Tuesday, 3/13/18

Warm-Up : 

How does a Van de Graaff Generator Work?

Today:   

Online Textbook Reading:  Chapter 18.1-18.2

Homework/Deadlines:  Test on Thursday

Class 57.5  Monday, 3/12/18

Warm-Up : 

1.  If you rub a balloon on your head and then hold it next to your hair, your hair is attracted to the balloon.  Why?

2.  Your hair may also stand on end after being rubbed by a balloon.  Why?

3.  The balloon may stick to the wall or ceiling.  Why?

4.  This all works better in drier air.  Why?

Today:   

Online Textbook Reading:  Chapter 8:  Linear Momentum and Collisions

Homework/Deadlines: Chapter 18.1 Practice  -- Static Electricity and Charge  Solutions

Class 57  Friday, 3/9/18

Warm-Up : 

The pictures on the right show a traditional water wheel followed by two Pelton Wheels.  What advantage is conferred by the Pelton Wheel design?

Today:   

Online Textbook Reading:  Chapter 8:  Linear Momentum and Collisions

Homework/Deadlines:  Mr. Pennington's Old Momentum Test.  Answers/Solutions.   Your test will be similar in format, but it will also have 1 coefficient of restitution problem and 1 ballistic pendulum problem.

Class 56.5  Thursday, 3/8/18

Warm-Up : 

1) How can we find the coefficient of restitution of this racquetball?

2) What's wrong with question number 1?

Today:   

Online Textbook Reading:  Chapter 8:  Linear Momentum and Collisions

Homework/Deadlines:   Coefficient of Restitution, Plus Various Momentum Problems Solutions (except 13-14)  Solutions to 13 and 14 

Class 56  Wednesday, 3/7/18

Warm-Up : 

Renault Modus (compact car) vs. Volvo wagon in a head-on crash. 

1.  What happens?

2.  Which is safer, a car that crumples in a crash or a car that is more rigid?

3.  When a ballistic pendulum is shot, at which point is there the greatest tension in its strings?

Today:   

Online Textbook Reading:  Chapter 8:  Linear Momentum and Collisions

Homework/Deadlines:  Due on Friday -- Coefficient of Restitution, Plus Various Momentum Problems Solutions (except 13-14)  Solutions to 13 and 14 

Class 55.5  Tuesday, 3/6/18

Warm-Up : 

When one Newton cradle ball hits another, the first ball stops and one other ball starts moving at the first ball's initial velocity.  Why don't two balls begin moving half as fast as the first one?  Or three balls at 1/3 the original speed?  Wouldn't momentum be conserved either way?

Today:   

Online Textbook Reading:  Chapter 8:  Linear Momentum and Collisions

Homework/Deadlines:   Complete ballistic pendulum for your launch.

 

Class 55  Monday, 3/5/18

Warm-Up : 

Suppose I stand a board on end and shoot it with a Nerf ® dart.  Am I more likely to knock the board over if I use a dart that sticks to the board or if I use a dart that bounces off of the board?  Why?

Today:   

Online Textbook Reading:  Chapter 8:  Linear Momentum and Collisions

Homework/Deadlines:   Complete ballistic pendulum calculations for launch 2 Use this spreadsheet to check your answers.  You'll need to make a copy.  Then enter the correct numbers into the yellow cells.

 

Class 54.5  Friday, 2/23/18

Warm-Up : 

1.  Explain how this jar lid closure works, in terms of Torque -- and especially T=Frsinθ -- and maybe F=kx.

Image result for towel2.  How does a whip work?

3.  How can an understanding of the Law of Conservation of Momentum turn a towel into a better whip?

Today:   

Online Textbook Reading:  Chapter 8:  Linear Momentum and Collisions

Homework/Deadlines:   

  • None
Class 54  Thursday, 2/22/18

Warm-Up : 

How does a helmet protect one's head from the force of an impact?

Today:   

Online Textbook Reading:  Chapter 8:  Linear Momentum and Collisions

Homework/Deadlines:   

Class 53.5  Wednesday, 2/21/18

Warm-Up : 

1.  What will happen if I hold a tennis ball on top of a basketball and drop them to the floor together?

2.  What if I reverse their positions?

3.  Why does this happen?

Today:   

Online Textbook Reading:  Chapter 8:  Linear Momentum and Collisions

Homework/Deadlines:   

Class 53  Tuesday, 2/20/18

Warm-Up :  No warm-up.  Test today.

Today:   

Online Textbook Reading:  Chapter 8:  Linear Momentum and Collisions

Homework/Deadlines:   

  • Car Projects are due tomorrow.  There will be no more class time set aside for car work.  We will begin linear momentum and collisions.
Class 52.5  Monday, 2/19/18

Warm-Up : 

A comet is essentially a point of orbit mass, so its moment of inertia can be calculated using the formula I = mr2.  The comet's rotational energy can be calculated using the formula KErot = 1/2 Iω2.  

1.   What happens to each of the components of the kinetic energy formula (I and ω) as the comet travels farther from and closer to the sun?

2.  No matter where the comet is in its orbit, what is the relationship between I and ω?

3.  Is a comet like a figure skater?

4.  How could these two formulas be used to understand the changes in KE as the comet orbits? 

  • Wnet = ΔKE.  

  • KE0 + PE0 = KEF + PEF

Today:   

Online Textbook Reading: Chapter 10

Homework/Deadlines:   

Class 52 Friday, 2/16/18

Warm-Up :  No warm-up today, in order to maximize work time

Today:   

  • Don't forget to work in your assigned area and to clean it up.  Do a hand swipe test.
  • Make sure you do these things today:
    1. Get a useful (with clear floor tile edges) video of your car accelerating from rest to top speed.
    2. Transfer your video, in full resolution, to a computer, and upload it to your Google drive.
    3. Collect data that will allow you to determine your car's front and rear axle momens of inertia.
  • What's due on Tuesday, when's the deadline for car improvement, awhat may happen if things aren't turned in on time.
  • One group submitted their spreadsheet for feedback.
  • New Car Project Information:
  • General Car Project Information

Online Textbook Reading: Chapter 10

Homework/Deadlines:   

Image result for quadcopter controlsClass 51.5 Thursday, 2/15/18

Warm-Up :  Image result for quadcopter

  1. A quadcopter has four propellers.  Why do the propellers alternate in their directions of rotation?
  2. How does a quadcopter achieve a yaw (rotation around a vertical axis) without also rising or sinking?  How does this work?
  3. How does a stationary quadcopter begin to fly forward?  Why does this work?

 

Today:   

Online Textbook Reading: Chapter 10

Homework/Deadlines:   

  • Car Projects (see links above) are due before school next Tuesday.
  • Test next Tuesday, similar to the two test reviews above.
  • If you want feedback on your car spreadsheet before you get your final grade, complete it by the end of the day on Today.  You will then have a chance to ask questions on Friday.
Class 51 Wednesday, 2/14/18

Warm-Up : 

1.  Why do tops wobble?

2.  For how long will Polaris remain the North Star?

Today:   

Online Textbook Reading: Chapter 10

Homework/Deadlines:   

Class 50.5 Tuesday, 2/13/18

Warm-Up : 

To wind up the car on the right, a string is hooked on a tab on one of the stair-step radii of the large chain ring, and the wheels are rotated backward until the rubber bands almost reach the chain ring.

1.  What is the purpose of the chain and gears?

2.  What is the purpose of the stair-step design of the front gear?

Today:   

Online Textbook Reading:  Chapter 10

Homework/Deadlines:   

Class 50 Monday, 2/12/18

Warm-Up : 

1.  What are some pros and cons of having a car that pops wheelies?  Why don't front wheel drive cars pop wheelies?  Does the wheelie concept have implications for 4-wheel drive cars?

2.  Suppose 20N is the highest rubber band tension that you can have without causing your car's wheels to slip.  How can you make your car go faster without increasing the tension?

3.  Suppose your wheels are slipping, and you can't afford to sacrifice tension in your rubber bands.  How can you stop the slipping?

Today:   

  • Problem solving.  Find ways to make your car go faster!  It's possible.
  • Car Info:
    • Goal:  Jump 1m horizontally or achieve speed of 3.4m/s. (10.7 frames/foot @120fps, or 21.4 frames/foot @240fps)
    • Car Project Information-- Rhino information, files, etc.

Online Textbook Reading:  

Homework:   Car Problem Set #1 -- Due tomorrow.Scanned Solutions  Video solutions for problem 1  Video solutions for Problem 2

Image result for dry limbs firewood driftwoodClass 49.5 Friday, 2/9/18

Warm-Up : 

Suppose you need to want to build a camp fire.  You have plenty of dry wood, but it's all big limbs that are too long to be manageable, and too thick to break over your knee.  Without using a saw or an axe, what's the best way to divide wood into smaller pieces?  Can you describe the proper technique?  One solution.

Today:   

  • Work on Cars:
    • Goal:  Jump 1m horizontally or achieve speed of 3.4m/s. (10.7 frames/foot @120fps, or 21.4 frames/foot @240fps)
    • Car Project Information-- Rhino information, files, etc.

Online Textbook Reading:  

Homework:   Car Problem Set #1 -- Due on Tuesday, 2/13

Class 49 Thursday, 2/8/18

Warm-Up : 

  1. How do falling cats always manage to land on their feet?
  2. Why do falling people flail their arms around?

Today:   

Online Textbook Reading:  

Homework:   None

Class 48 Tuesday, 2/6/18

Warm-Up : 

In the picture on the right, the wheel is spinning, and the guy is sitting on a chair that rotates freely.  What will happen when he flips the wheel over so that it rotates in the opposite direction?

Today:   

Online Textbook Reading:  

Homework:   10.5 Angular Momentum Practice --  Practice Key

Class 47.5 Monday, 2/5/18

Warm-Up : 

1.  How does one "pop a wheelie" on a bike? In a car?

2.  How could we calculate the conditions that are necessary for a wheelie to be popped?

Today:   

Online Textbook Reading:

Homework:   

Class 47 Thursday, 2/2/18

Warm-Up : 

A sphere, a cylinder, a ring, and a frictionless box are released from rest at the top of ramp.  Their masses and heights are identical.

1.  Rank the objects according to their arrival times at the bottom of the ramp.

2.  The round objects are affected by friction.  Would the result be different in a totally frictionless situation?  Explain.

3.  If the objects hit a vertical, frictionless wall at the bottom of the ramp, what motions would continue after impact?

Today:   

Online Textbook Reading:

Homework:    Chapter 10.4 -- Rotational Kinetic Energy Practice -- Practice Key

Class 46.5 Thursday, 2/1/18

Warm-Up : 

1.  How could you measure the moment of inertia of a rubber band car's drive wheel and axle?

2.  How can you accurately measure a rubber band car's top speed?

Today:   

Online Textbook:

Homework:    None

Image result for compound bow drawnClass 46 Wednesday, 1/31/18

Warm-Up : 

1.  Where does a compound bow store most of its energy?

2.  What purpose(s) do the pulleys of a compound bow serve?

Today:   

Online Textbook:

Homework:    Chapt 10.3 Practice -- Dynamics of Rotational Motion: Rotational Inertia --Key

Class 45.5 Tuesday, 1/30/18

Warm-Up : 

The rubber band-powered car in the top of the diagram is powered by a rubber band that is hooked directly onto the drive axle. 

The rubber band of the car on the bottom  is connected to the drive axle by a string. 

What are some pros and cons of each method?

Today:   

Online Textbook:

Homework:    Kinematics of Rotation Practice -- Key

Class 45 Monday, 1/29/18

Warm-Up : 

1.  Suppose a car's tires are rotating with an angular velocity of 94rad/s.  What is the car's speed if the tires have a radius of 0.3m -- and the wheels are not slipping, relative to the road's surface?  Estimate or calculate the speed in miles per hour.

2.  What does the tire size "205/75R15" mean?

Today:   

Homework:    Angular Acceleration Practice -- Key

Class 44.5 Friday, 1/26/18

Warm-Up : 

If this car's rear wheels' angular velocity is 100rpm (and the wheels are not slipping), what is the car's velocity in m/s?

Today:   

Homework:   None

Class 44 Thursday, 1/25/18

Warm-Up :  Practice with radians

1.  360º = _____ radians

2.  90º = _____ radians

3.  2 radians = _____ degrees

Today:   

  • New Concepts: 
  • Cars:
    • Car Project Information-- Rhino information, files, etc.
    • Laser cut and assemble your cardboard car.
    • Some things to try if parts of your car are not getting cut on the laser cutter:
      • Select all of the lines to cut, and do another "make 2-D drawing."  Then delete the old layout and try to cut with the new 2-D drawing.
      • Select your parts to cut.  Then select "hairline" in the properties tab on the right of the screen.
      • Select your parts to cut.  Then change the print color to "red" in the properties tab on the right of the screen. 

Homework:   Torque Practice (Pennington)   Torque Practice Solutions

Class 43.5 Wednesday, 1/24/18

Warm-Up : 

 Torque = Fr, where F is the force applied perpendicularly to the radius of rotation and r is the distance of the point of application to the center of rotation.

The torque acting on and transferred by a rotating body is the same at any radius.

Torque units may be Nm or N·m.

1)  Calculate the torques applied by the red rubber band to each car's drive wheels.

2)  Calculate the forces applied by each of the cars to the road.

Today:   

Homework:   If you're behind on the car project, get caught up.  You can do some things online.  Rhino is on library computers and many science computers.

 

Class 43 Tuesday, 1/23/18

Warm-Up : 

Suppose you're whittling on a ski lift.  You have some excess wood that you'd like to toss out, but you don't want it to cause problems for skiers, so you want to drop it so that it falls behind the base of a ski lift pole. 

1)  If your chair is traveling horizontally at a rate of 3m/s and you're dropping the wood a vertical distance of 5m, how far in advance of your target should you release the wood?

2) Why might a skier whittle on the lift? 

Today:   

  • Return papers.

  • Look at and discuss midterms.  Verify your grade and then return your exam.

  • Work on cars.

    1. Design your car in Rhino.

    2. Open and save a copy of this template -- Car project slideshow template.

    3. Share your slideshow with your partner and paste a link into this form.

    4. In Rhino, add color to your car parts, so that they can be distinguished from one another.  Create at least one jpeg rendering and paste it into slide #2 of your slideshow.

    5. Save your completed and assembled car design in Rhino.

    6. In Rhino, lay out your car parts for laser cutting on a virtual 23.5" x 11.5" rectangle.  Save this file under a new name (e.g. "Jimbo version 1 layout"). 

    7. Paste a picture of these parts in slide #3 of your slideshow.

    8. Pass the quiz over -- PDF -- laser cutter rules and produres.

    9. Watch Video -- how to laser cut in the Fab Lab using Rhino.

    10. Go to the Fab Lab and cut your parts out of cardboard.

    11. Assemble your cardbaord prototype.  Take a picture and paste it into slide #4 of your slideshow.

  • Project Stuff relating to Rhino -- Rhino information, files, etc.

Homework:   

Class 42 Friday, 1/12/18

Warm-Up : 

1. What kind of rear tires do dragsters use?http://iml.jou.ufl.edu/projects/spring06/gregorzek/tires.html

2. Why do drivers do a "burnout" before each race?

3.  How else do dragsters increase traction?  http://en.wikipedia.org/wiki/Top_Fuel

4.  What do dragster tires look like in slow motion? http://www.youtube.com/watch?v=3Ug6w4ZjwVo&feature=related

5.  Why and how do vehicles "pop wheelies?" 

 

Popular Mechanics Dragster Info

Today:   

  • Test review

  • Work on cars.  See class #41, below, for details.

Homework:   

  • Prepare for the midterm
Class 41 Thursday, 1/11/18

Warm-Up : 

The picture on the right shows one of the elasticar bearings. 
1.  Which part(s) of the bearing should touch the frame of your car?
2.  Which part(s) of the bearing should touch your car's axle?
3.  Which parts can touch your wheel?
4.  For a non-drive axle, your answers to 1-3 could be different.  Explain.

Today:   

  • Work on cars.

    1. Design your car in Rhino.

    2. Open and save a copy of this template -- Car project slideshow template.

    3. In Rhino, add color to your car parts, so that they can be distinguished from one another.  Create at least one jpeg rendering and paste it into slide #2 of your slideshow.

    4. Save your completed and assembled car design in Rhino.

    5. In Rhino, lay out your car parts for laser cutting on a virtual 23.5" x 11.5" rectangle.  Save this file under a new name (e.g. "Jimbo version 1 layout"). 

    6. Paste a picture of these parts in slide #3 of your slideshow.

    7. Pass the quiz over -- PDF -- laser cutter rules and produres.

    8. Watch Video -- how to laser cut in the Fab Lab using Rhino.

    9. Go to the Fab Lab and cut your parts out of cardboard.

    10. Assemble your cardbaord prototype.  Take a picture and paste it into slide #4 of your slideshow.

  • Project Stuff relating to Rhino -- Rhino information, files, etc.

Homework:   

Class 40.5 Wednesday, 1/10/18

Warm-Up : 

1.  What do the highlighted yellow directions mean?

Today:   

Homework:   

Class 40 Tuesday, 1/9/18

Warm-Up : 

1.  How might the length of a rubber band car affect its performance?

2.  What is the white stuff billowing out from under the car in the warmup photo from last class?

Today:   

  • I forgot two formulas on the formula sheet: 

  • Updated Semester 1 Formulas

  • Rhino Work: 
    • Manipulate this sample car design
      • How to create photos/renderings
      • How to prepare the car for laser cutting -- wood and cardboard. 
        • Rotate and lay out flat
        • Arrange on a virtual board
        • Scale for creating in cardboard.
          • Our wood is thicker; to switch media, scale down 0.684 or scale up 1.462.  Adjust bearing holes to 0.86" and axle holes to 0.3125" diameters.
    • Make a simple car design together
      • Importing the axles and bearings -- or just keeping those from the sample car.
      • Working with the cylinder command
      • Copy command, under the transformation tab
      • Other commands listed in the link below
  • Project Stuff relating to Rhino -- Rhino information, files, etc.
  •  

Homework:   

  • prepare for the midterm
Image result for wheels spinning outClass 39.5 Thursday, 1/7/18

Warm-Up : 

Suppose your rubber band car doesn't have enough traction.  The wheels are spinning out. 

1.  What is the root of the problem?

2.  What are some ways to prevent your wheels from slipping?

3.  Do your solutions have costs?  If so, what are they?

Today:   

Homework:   

Class 38.5 Thursday, 1/4/18

Warm-Up : 

A 2kg weight is held at the bottom of a dangling spring that has a spring constant of 20N/m.  After the weight is released, how far will it fall before it bounces back up?  For easy calculations, assume that g=10m/s2.

Remember,

Today:   

Homework:   

Class 38 Wednesday, 1/3/18

Warm-Up : 

Equations (when x = distance stretched):  Fspring = kx        PEspring =

1. If a spring has a "stiffness constant" k = 20N/m, what force is required to stretch the string a distance of 2m?

2.  How much energy is stored in this spring when it is stretched 2m?

3.  If this spring energy were used to accelerate a 20kg mass, what maximum velocity could the spring give this mass (assuming no energy is lost to friction)?

Today:   

Homework:   

Class 37.5 Tuesday, 1/2/18

Warm-Up : 

In either case on the right, if the weight is 10N, how much force must be applied to rope to lift the weight?  Why? (Ignore the masses of the pulleys and rope, and assume 100% efficiency.)

Today:   

  • Pulley demo

  • Last year's Car Project Outline.  Begin thinking about a car design.

  • How to secure a load with a bowline and a Trucker's Hitch
    • Bowline:        Slippery Half Hitch:        Slip knot:        How to secure a box with a Trucker's Hitch:

     

Online Textbook (OpenStax) Reading: 

Homework:   

  • Prepare to design a cardboard box  -- practice for making a cardboard car, and a wooden car.  You may use any CAD software, but I will show you how to use Rhino.  Watch the video below.
Class 37 Friday, 12/22/17

Warm-Up : 

In either case on the right, if the weight is 10N, how much force must be applied to rope to lift the weight?  Why? (Ignore the masses of the pulleys and rope, and assume 100% efficiency.)

Today:   

Online Textbook (OpenStax) Reading: 

Homework:   

  • None
Class 36.5 Thursday, 12/21/17

Warm-Up : 

Quiz Today --  No warm-up

Today:    Quiz

Online Textbook (OpenStax) Reading: 

Homework:   

  • None
Class 36 Wednesday, 12/19/17

Warm-Up : 

1.  Is lying okay?

2.  What is cheating?  Is cheating okay? 

3.  Is there a difference between lying and cheating?

4.  Is committing a crime a form of cheating?

5.  What does snitch mean?

6.  What should you do when you know someone is lying or cheating?  What if you think they are, but you're not sure?

7.  What should you do when you have been told that someone is lying or cheating?  What should a teacher do? 

 

Today:   

Online Textbook (OpenStax) Reading: 

Homework:   

  • Prepare for the quiz
Image result for wedge mechanical advantageImage result for hockey stick fulcrumImage result for boat winchClass 35.5 Tuesday, 12/19/17

Warm-Up : 

The pictures on the right all show simple machines.  Simple machines allow the same work to be done with more convenient combinations of force and distance. 

1.  Which "machine" is fundamentally different? Why?

2.  Identify the task in each picture.

3.  For each picture, identify the machine (s).

4.  For each machine, tell how the machine alters the distance over which force must be applied by the human using the machine.

5.  How does the machine alter the force that the human must apply?

Today:   

  • Change of plans -- quiz Thursday.  It will be short.  Today -- finish the bungee jumps.  Then start going over the homework problems.

  • Finish Bungee Jump Activity 

    • Conduct an egg drop

    • Individually, make sure that your spreadsheet is complete and has a working graph.  Fill out the submission form if you haven't already.

    • As a group, fill out the back of the first page of the handout.  Turn in one for your group.

  • Check/review homework: #4-10 of "Spring Energy and Review Problems"  (solutions)

  •  

Online Textbook (OpenStax) Reading: 

Homework:   

  • Prepare for the quiz
Class 35 Monday, 12/18/17

Warm Up :  

1.  When does each of these energy conservation equations apply to the diagram below?

2.  Would your answer change if this were a completely frictionless environment?

 

Today:   

  • Continue Bungee Jump Activity  Bungee Spreadsheet Template

  • Confirm that your spreadsheet works.  Enter these data from columns A and B and see if you get the same answers in the yellow cells.

  • Complete the bungee speadsheet graph. 

  • Bungee jumps -- weight followed by an egg.

Online Textbook (OpenStax) Reading: 

Homework:   

Class 34.5 Friday, 12/15/17

Warm Up :  

1.  What does the "sisyphus train" do?

2.  How did it get that nickname?

3.  What are conservative forces?

Today:   

Online Textbook (OpenStax) Reading: 

Homework:   

  • Complete the bungee speadsheet to determine the low point for a 200g jumper.
Class 34 Thursday, 12/14/17

Warm Up :  

An ideal spring has a constant, k, that describes the relationship between stretch distance and tension.  The units for k can be N/m. 

Suppose a screen door spring has a spring constant k = 40N/m.

1.  What is the tension in the spring when it is stretched 1m?

2.  What is the tension in the spring when it is stretched 20cm?

3.  How much work is required to stretch the spring by 1m, starting with 0N of tension in the spring?

4.  How much work is required to stretch a spring x meters if its spring constant is k?

5.  PEspring = ?

Today:   

Online Textbook (OpenStax) Reading: 

Homework:   

  • Complete the first two tables of your bungee jumper spreadsheet.
Class 33.5 Wednesday, 12/13/17

Warm Up :  

1.  A 1kg ball travels directly upward.  Its initial KE = 8J.  How much kinetic energy will it have when it reaches its highest point? (ignore air resistance)

2.  How much potential energy (PE) will it have when it reaches its highest point?

3.  As the ball rises, what is doing work on what?

4.  What is the formula for gravitational PE, and where does it come from?

Today:   

Online Textbook (OpenStax) Reading: 

Homework:   

Class 33 Tuesday, 12/12/17

Warm Up :  

1.  Calculate the work done according to each of the graphs.

Today: 

Online Textbook (OpenStax) Reading: 

Homework:   

Class 32.5 Monday, 12/11/17

Warm Up :  

1.  Read statement from Mr. Reardon -- forgot on Friday.

2.  Is tension the same in all parts of the slinky on the right?

3.  What happens when you suspend a slinky (as shown in the photo on the right) and then drop it?

1st Video

2nd video

Supersized Slinky

one answer

Today: 

Online Textbook (OpenStax) Reading: 

Homework:   

  • Work/energy prolems?
  • Slides are due tomorrow -- Briefly research an application of circular motion.  Create a slide sharing what you've found.  Due on Tuesday.  The slideshow and a "sign-up sheet" have been shared with you
Class 32 Friday, 12/7/17

Warm Up :  

No warm-up.  Read statement from Mr. Reardon.

Today: 

  • Test

  • work on your slide (see homework, below)

Online Textbook (OpenStax) Reading: 

Homework:   

Class 31.5 Thursday, 12/7/17

Warm Up :  

1.  How does this yo-yo work? What do the springs and steel balls do?

2.  If you graphed the velocity of a yo-yo, would it look like this?

 

Today: 

Online Textbook (OpenStax) Reading: 

 

Homework:   

  • Prepare for tomorrow's test
  • Briefly research an application of circular motion.  Create a slide sharing what you've found.  Due on Monday.  The slideshow and a "sign-up sheet" have been shared with you
Class 31 Wednesday, 12/6/17

Warm Up :  

1.  Does it take longer for the satellite to travel from point A to point B or from point C to point D?

2.  How can Kepler's 2nd Law be used to prove the answer to #1?

Today: 

Online Textbook (OpenStax) Reading: 

Homework:   

  • Go over the study guide, homeworks, and the ellipse activity.  Come to tomorrow's class with any questions that you would like to have answered before the test on Friday.
Class 30.5 Tuesday, 12/5/17

Warm Up :  

1.  What is a geosynchronous satellite?

2.  What's the difference between a geosynchronous orbit and a geostationary orbit?

3.  What is a space elevator?

4.  Graveyard orbit?

5.  Please do not leave anything permanent or semi-permanent (like stickers) in the classroom.

Today: 

Online Textbook (OpenStax) Reading: 

Homework:   

Class 30 Monday, 12/4/17

Warm Up :  

1.  How can the coin be removed from the disc pictured on the right? -- without banging the disc with or against something

2.  What is the difference between elevation and orbital radius?

Today: 

Online Textbook (OpenStax) Reading: 

Homework:   

Class 29.5 Friday, 12/1/17

Warm Up :  

1.  How are g-forces dangerous to pilots?

2.  How does your body sense weight and weightlessness?  What causes "butterflies in the stomach?"

3.  How does an accelerometer work?

Today: 

Online Textbook (OpenStax) Reading: 

Homework:   Practice problem #11.

Class 29 Thursday, 11/30/17

Warm Up :  

1.  During what month are we closest to the sun?  When are we farthest?

2.  Rank the seasons in order of length. Answer

Today: 

Online Textbook (OpenStax) Reading: 

Homework:   

  • Complete problems 6, 8, 10, 12, and 13.
  • Finish elliptical orbits activity
Class 28.5 Wednesday, 11/29/17

Warm Up :  

Are astronauts weightless when they are in the international space station?  Is this candle weightless?

Today: 

  • Return Quizzes

  • Check/discuss homework

Online Textbook (OpenStax) Reading: 

Homework:   

  • None
Class 28 Tuesday, 11/28/17

Warm Up :  

No warm-up.  Quiz.

Today: 

Online Textbook (OpenStax) Reading: 

Homework:   

Class 27.5 Monday, 11/27/17

Warm Up :  

Consider an object tied to a string and swinging in horizontal circles.  What forces are acting on the object?

Today: 

Online Textbook (OpenStax) Reading: 

 

Homework:   

  • Prepare for quiz
Class 27 Friday, 11/17/17

Warm Up :  

From last year's EPS 200 class...

The Sun, Earth, and Moon are continually spaghettifying one another.  We see the effects of this spaghettification in the form of tides.

1.  What causes spaghettification and tides?

2.  How much gravitational force do the Sun and Moon each exert on 1,000,000 pounds of water?

3.  There are tides on the Moon.  Explain.

4.  Why do we always see the same side of the moon?

5.  Is the Earth's 24 hour rotational period speeding up or slowing down over time? Answer

Perplexing questions:  Are tides equally high on the near and far side of the Earth from the Moon?  Are high tides equally high during full and new moons?  Why or why not?  How would one model this?

Today: 

Online Textbook (OpenStax) Reading: 

Homework:   

  • Quiz on Tuesday after break.  See practice quiz above.
Image result for car skidding to a stopClass 26.5 Thursday, 11/16/17

Warm Up :  

If you need to stop a car quickly, why should you avoid locking the tires or skidding?  

Today: 

  • Introduction to Rhino

  • Work time -- practice quiz or rocket analysis

Online Textbook (OpenStax) Reading: 

Homework:   

Class 26 Wednesday, 11/15/17

Warm Up :  

1.  In the Energy Skate Park simulation on the right, what happens to kinetic and potential energy as the skater gets higher and lower?

2.  There is no thermal energy.  What does that tell us?

3.  What happens to the total amount of energy as the skater moves?

4.  Can you tell from the picture and diagram which way the skater is moving?

5.  If you're considering the situation on the right from a systems of equations perspective, how many variables and equations did we use to find T1 and T2?

6. And, by the way, where would you come out if you dropped frictionlessly straight through the center of the Earth?  (antipodes map)

Today: 

Online Textbook (OpenStax) Reading: 

Homework:   

Class 25.5 Tuesday, 11/14/17

Warm Up :  

In the absence of friction, if you made a hole through the center of the Earth, it has been shown that you would come out the other side in approximately 42 minutes. 

1. What else would happen to you? 

2. Where would you come out? 

3. The 42 minutes has been shown to be wrong.  Why?  Would the trip actually be longer or shorter?

4.  What if there were air resistance?

(antipodes map)

Excel spreadsheet -- falling through the earth

Today: 

Online Textbook (OpenStax) Reading: 

Homework:  Complete #2 of Masses Hanging and Dragged at Angles Solutions to #1 and #2

Image result for tension in wire physics move a carClass 25 Monday, 11/13/17

Warm Up :  

The picture on the right shows how a chain can be used to pull a stuck car out of the mud.  All that is required is a small sideways force applied to the center of the chain.  Why does this work?

Today: 

Online Textbook (OpenStax) Reading: 

Homework:  Complete #4 of Masses Hanging and Dragged at Angles solutions to 3 and 4

Class 24.5 Friday, 11/10/17

Warm Up :  

How many 100 psi water bottles would it take to launch a human?

Today: 

Online Textbook (OpenStax) Reading: 

Homework:  None

Class 24 Thursday, 11/9/17

Warm Up :  

Let's use this air density calculator and the current weather conditions to determine the density of the air outside.

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

  1. Complete #3 from Bodies on Inclines  Answers (and some solutions ) to Bodies on Inclines
  2. If your spreadsheet does not work, compare it to mine (here's a link to mine; make a copy) and fix your formulas.  Try to understand what went wrong and why.  If you can't figure it out, or if you don't understand why something is wrong, see me during Flex.
Class 23.5 Wednesday, 11/8/17

Warm Up :  

1.  How many square meters is one square centimeter?

2.  The diagram on the right comes from this online Water rocket simulator.  What effect does each of the parameters have on rocket performance?

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

Complete #2 in Bodies on Inclines  Answers (and some solutions ) to Bodies on Inclines

Class 23 Tuesday, 11/7/17

Warm Up :  

1.  If there is no friction acting on the block, what is its approximate downhill acceleration?

2.  If there is friction between the block and the ramp, describe all of the individual forces that are acting on the block.  You may assume that the block and ramp are in a vacuum.

3. Approximate the value of µs that is necessary to prevent the block from sliding.

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

Complete 1a and 1b in Bodies on Inclines  Answers (and some solutions ) to Bodies on Inclines

 

Image result for weather vaneClass 22.5 Monday, 11/6/17

Warm Up :  

1.  How does a weather vane work?

2.  If you drop a model rocket from a great height, which end will hit the ground first?  Why?

3.  If you drop a hammer from a great height, which end will hit the ground first?  Why?

4.  What part of a hammer has the greatest terminal velocity.

5. If you want your rocket to fly "straight," what design features should you include?

Today: 

  • Water Rocket Project.

  • Finish spreadsheets.  If your computer is slow, you may want to try downloading the spreadsheet and working on it as an excel document.

Online Textbook (OpenStax) Reading: 

Homework: 

Finish the spreadsheet before next class.  Submit the spreadsheet using this form.

Class 22 Friday, 11/3/17

Warm Up :  

Consider the same mass, string, and angle as before, but now the mass is exposed to the oncoming air.  The angle is still constant.  [Air density = 1.2kg/m3.  Cd sphere = 0.45.  Asphere = 0.05m2]

1. Describe the motions of the mass and the train car in qualitative terms.

2.  What is the tension in the string?

3.  Describe the motions of the mass and the train car in quantitative terms.

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

None

 

Class 21.5 Thursday, 11/2/17

Warm Up :  

A 1kg mass is suspended by a string from the ceiling of a train car.  The angle shown remains constant.

1. Describe the motions of the mass and the train car in qualitative terms.

2.  What is the tension in the string?

3.  Describe the motions of the mass and the train car in quantitative terms.

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

Consider the warm-up diagram, above.  Suppose the indicated angle is 30º and the mass is 3kg.  In this case,  what is the tension in the string?  What is the train's acceleration? 

Class 21 Wednesday, 11/1/17

Warm Up :  No warm-up

Today: 

  • Test

Online Textbook (OpenStax) Reading: 

Homework: 

Class 20.5 Tuesday, 10/31/17

Warm Up :  

A water rocket contains pressurized air and water.

1.  Is the "fuel" the water, the air, or both?

2. What determines the force of drag acting on a water rocket?

Today: 

  • One change regarding the test -- format of the extended problem.
  • Click here to see the test format
  • Water Rocket Project.  Build and launch water rockets.  The goal is to create a rocket with the highest speed at the moment of impact.  You will also complete the Water Rocket Analysis, which requires a trajectory spreadsheet incorporating drag.

  • Begin working on Trajectory Spreadsheets With Drag

Online Textbook (OpenStax) Reading: 

Homework: 

  • Study.  Test next class.
Class 19.5 Friday, 10/27/17

Warm Up :  

What if I put a large rock on my head, with a 2"x4" on top of the rock, and then I have someone hammer a nail through the 2"x4"?  Is that a good idea?

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

  • Study
Class 19 Thursday, 10/26/17

Warm Up :  

Why can no one in the world can throw a wiffle ball with a force greater than about 60N (13.5 pounds)?

 

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

  • Prepare to ask questions about the test.
Class 18.5 Wednesday, 10/25/17

Warm Up :  

The figure on the right shows some masses connected by an unstretchable chain of negligible mass that travels over a frictionless, massless pulley in a vacuum.  Assume that each object has a mass of approximately 1kg and a weight of approximately10N.

1.  What net force is acting on the system of objects?

2.  What are the objects' accelerations?  (magnitude and direction)

3.  How do the rope tensions, T1, T2, and T3 compare?  Rank them according to magnitude.

 

Today: 

  • Test next monday
  • Check/discuss homework.  Finish notes.  Friction notes

Online Textbook (OpenStax) Reading: 

Homework: 

Image result for cat falling from buildingClass 18 Tuesday, 10/24/17

Warm Up :  

Emergency clinic records of 132 cats that jumped from windows of buildings showed a 90% survival rate.  The average drop was 5.5 floors. 

Injuries increased with increasing heights up to 7 floors. When cats fell from over 7 floors, they actually suffered from “less injuries.” 

1. When does a falling cat experience zero net force?

2. When is a falling cat a "free-falling" cat?

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

Class 17.5  Monday, 10/22/17

Warm Up :  None

Today: 

  • Mr. Stapleton gone. Work on homework
Class 17 Wednesday, 10/18/17

Warm Up :  

1. How does NASA simulate weightlessness?

2. You are trying to transfer some drippy sauce across a dinner table using only a drippy spoon.  The sauce needs to go from the pot to your plate without dripping.  Touching only the spoon, how can you make this happen?

Today: 

Online Textbook (OpenStax) Reading: 

Homework:  Due next Tuesday -- Mr. Stapleton will be gone on Monday

Class 16.5 Tuesday, 10/16/17

Warm Up :  

One way to find the center of mass (a.k.a. balance point) of a stick is to support it with two level hands and then slowly move those two hands together until they meet under the stick's center of mass.

Why does this method work?

Today: 

  • Check/discuss homework.
  • A2, I was reminded of this yesterday... Launcher Grading

Online Textbook (OpenStax) Reading: 

Homework: 

Class 16 Monday, 10/16/17

Warm Up :  

Tension is the force exerted on and exerted by a stretched rope. 

1.  If we assume that the rightmost team is winning in the picture, how does the tension on the right half of the rope compare to the tension on the left half of the rope?

2.  In which direction does the force of tension act?

3.  Does the winning team pull the hardest?

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

Class 15.5 Friday, 10/13/17

Warm Up :  

There is a heavy object tied to the ceiling with a string.  Another segment of the from the same roll of string is hanging from the object.  I am going to pull on the bottom string until one of the two strings breaks.  Which string is going to break first?  Why?

Today: 

  • Return Tests

Online Textbook (OpenStax) Reading: 

Homework: 

  • None
Class 15 Thursday, 10/12/17

Warm Up :  

No warm up today

Today:  Test

Online Textbook (OpenStax) Reading: 

Homework: 

  • Optional reading -- Newton's laws through 2nd law
Class 14.5 Tuesday, 10/11/17

Warm Up :  

It is possible to pull the paper from under a dry erase pen without touching or tipping the pen.  Usually, however, the pen falls over.  Why does the pen usually fall?  How can one do this without tipping the pen?  Why does that method work (sometimes)?

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

  • Prepare for test
Class 14 Monday, 10/9/17

Warm Up :   No warm-up today.  Get ready to shoot.

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

  • Test is Thursday, not Friday.  Review your homeworks and practice tests and come to tomorrow's class ready to ask questions.  If you want more practice, remember that an optional practice test was handed out on class 13, below.
Class 13.5 Friday, 10/6/17

Warm Up :   No warm-up today

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

  • See yesterday.
Class 13 Thursday, 10/5/17

Warm Up :

Can you guess the top 3 "hobbies/interests" of students in B3/4 and B5/6 Physics 200?

Today: 

  • Check/discuss homework solutions.
  • Projectile Launcher Project (contest)
  • Launcher Grading
  • Today:
    • Fine tune rubber band combinations and calibrate launchers today.  Create a muzzle velocity calibration graph.  Contest problems will be given out after class.
    • Take your shot.
    •  Real contest on Monday.
    • Get the contest problems tomorrow.
  • Test next Wednesday Friday.

Online Textbook (OpenStax) Reading: 

Homework: 

Class 12.5 Wednesday, 10/4/17

Warm Up :

1)  Based on the diagram to the right, provide definitions for precision and accuracy.

2) In the projectile contest your launcher must be able to fire projectiles at muzzle speeds between 6m/s and 10m/s.  If your launcher has a maximum muzzle velocity of 11m/s, and your friend's has a maximum muzzle velocity of 20m/s, whose launcher is more precise?  Why?

3)  Describe the perfect rubber bands for this launcher competition.

Today: 

  • Check/discuss homework solutions.
  • Projectile Launcher Project (contest)
    • Tentative plan: 
      • Fine tune rubber band combinations and calibrate launchers today.  Create a muzzle velocity calibration graph.  Contest problems will be given out after class.
      • Work on contest practice problem for homework.
      • Practice contest tomorrow.  Real contest on Monday.
      • Test next Wednesday.

Online Textbook (OpenStax) Reading: 

Homework: 

  • Solve this problem for your launcher, using your spreadsheet and your launcher velocity calibration graph.  Be ready to test your solution by shooting tomorrow.
Class 12 Tuesday, 10/3/17

Warm Up :

At the angle shown, can the projectile launcher hit the target?  If not, how should the launcher be adjusted?

Today: 

  • Check homework.  Solutions
  • Sour Smileys for Tommy and Brody
  • Projectile Launcher Project (contest)
    • Create a spreadsheet that will:
      • calculate/show the trajectory of a projectile
      • calculate your launcher's muzzle velocity when you shoot it horizontally from a stool
      • provide the correct launcher power setting to achieve any velocity
    • You may use this Link to Spreadsheet Template.
    • Complete the practice problems in the contest overview.
    • If there's time, begin creating your launcher calibration graph.
    • Tentative plan: 
      • Spreadsheets today
      • Calibrate launchers tomorrow.  Contest problems will be given out after class.
      • Work on contest solutions for homework tomorrow.
      • Contest on Friday.

Online Textbook (OpenStax) Reading: 

Homework: 

Class 11.5 Monday, 10/217

Warm Up :

Suppose I want to find the time it takes for cannonballs to fall.  I want fall times for all of the following heights: 40m, 44m, 46m... 80m?  How could I create a spreadsheet that would quickly calculate all of these times?

Today: 

  • Check homework.  Solutions
  • A1 -- finish shooting.  Can anyone beat 6cm (from 10 feet, @40º)?
  • Work time -- homework problems
  • Tomorrow (probably) -- Projectile spreadsheets.

Online Textbook (OpenStax) Reading: 

Homework: 

Class 11 Friday, 9/29/17

Warm Up :

The diagram on the right is hyperlinked comes from the Hyperphysics website.

1.  To what conditions can the range formula be succesfully applied?

2.  According to the formula, what value of θ gives the greatest range?

3.  Take a look at what else is on that website.

Today: 

  • Check homework.  (solutions)
  • Wrap-up Projectile Launcher Activity 1 (spreadsheet to check calculations).
    • Check your power setting using a stool and a horizontal shot -- see if the muzzle velocity is the same as yesterday.  If not, recalculate muzzle velocity.
    • Find an unobtrusive place to practice shooting at a wall.  Choose some distance from the wall, and incline your launcher at some angle. For your given muzzle velocity, calculate the height at which the projectile should hit the wall.  Try it.  If there is a big discrepancy between your calculations and the actual impact point, try to figure out why.  In a worst case scenario, make note of how your calculations differ from the actual shot.  Try shooting at different distances from the wall and at different angles.
    • Contest -- When there are 25 minutes remainging in class, return to the classroom for a short shooting competition.  Here are the parts:
      1. Turn in your projectiles.
      2. Problem is revealed.  10 minutes to solve.
      3. 1 shot per team. 
      4. Closest shot wins (fruit snack/tootsie pop)
  • Clean up.  Push chairs and stools into place.

Online Textbook (OpenStax) Reading: 

Homework: 

Class 10.5 Thursday, 9/28/17

Warm Up :

A projectile launcher is inclined at a 70 degree angle, relative to horizontal.   It is pointed at a vertical wall a horizontal distance of 5m away from the muzzle.  If the muzzle velocity of the projectile is 8m/s, how would you find the Δy will the projectile experience between leaving the launcher and hitting the wall?

Today: 

  • Check homework. (solutions)
  • Hints on how to solve tonight's homework problems.
  • Continue Projectile Launcher Activity 1 (spreadsheet to check calculations).  Try to arrive at a consistent muzzle velocity for your chosen power setting.
  • Clean up

Online Textbook (OpenStax) Reading: 

Homework: 

Class 10 Wednesday, 9/27/17

Warm Up : A green hunter and a blue hunter point their guns directly at a fake orange monkey and then fire simultaneously.  Just as the two hunters fire their guns, the monkey slips and freefalls from the treetop. 

1. How can we show, mathematically, that the blue hunter's projectile will hit the monkey?

2.  Suppose you launch a projectile at an angle above horizontal.  The projectile flies through the air and lands back at the starting height.  Which velocity component would be most helpful in determining the projectile's time aloft -- Vx or Vy?  Why?

3.  If you were to launch the same projectile at a different angle above horizontal.  This time the projectile collides with a wall that is 4m from the starting point.  In this case, which component of velocity would be most helpful in determining the time aloft?  Why?

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

 

Class 9.5 Tuesday, 9/26/17

Warm Up : A green hunter and a blue hunter point their guns directly at a fake orange monkey and then fire simultaneously.  Just as the two hunters fire their guns, the monkey slips and freefalls from the treetop. 

1. Where does each hunter's projectile end up, relative to the monkey?  High, low, or in the monkey?

2.  How would the result have been different if the monkey stayed in position at the top of the tree?

3.  Do the answers to these questions depend on the bullet velocities?

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

Class 9 Monday, 9/25/17

Warm Up :  

1.  What is happening to Vx and Vy at each moment in this photograph?

2.  For each frame, how can we draw proportionally accurate Vx and Vy vectors on the diagram?

3.  Consider the second diagram, below.  How does the magnitude of the river's velocity affect the boat's crossing time?

Today: 

Next Class:  2-D Kinematics with acceleration.

Online Textbook (OpenStax) Reading: 

Homework: 

Image result for boat crossing a riverClass 8.5 Friday, 9/22/17

Warm Up :  

1.  What is the difference between ground speed and air speed?

2.  Suppose you have a medium (such as water or air) that is moving with a certain velocity, relative to the Earth.  Also suppose you have an object moving through that medium.  The object has one velocity relative to the medium and a different velocity relative to the Earth.  Of the three velocities that are highlighted, which one is most likely to be the resultant velocity in a physics problem?

3.  Draw head to tail diagrams for these situations:

a. Vriver=3m/s South, Vboat=2m/s West, Vboat relative to water =?

b. Vplane air velocity = 200m/s N,  Vwind=50m/s E, Vplane =?

c. Vperson on train=20m/s W, Vperson relative to train=4m/s S, Vtrain =?

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

Class 8 Thursday, 9/21/17

Warm Up :  

1.  What are sine, cosine, and tangent?

2.  Use trigonometry to find the missing vector magnitudes on the right.

Today: 

Online Textbook (OpenStax) Reading: 

Homework: 

  • There will not be explicit notes on every aspect of vector addition, but we will practice it.  In lieu of complete notes, refer to the textbook sections.
  • Finish Analytical Vector Addition Practice -- orthogonal and random vector assignments (above)
  • Classic River Problem
Class 7.5 Wednesday, 9/20/17

Warm Up :  

1.  Suppose the two vectors on the right represent two forces acting on the clam.  In what direction will the clam accelerate?  What will be the magnitude of the net force accelerating the clam in that direction?

2.  The diagram on the right shows a top view of a train car that is moving at a rate of 2m/s.  You are in the car.  In which direction and how fast should you walk in order to have the intended velocity shown on the right.

Today: 

  • Return tests

  • Take a look at the online textbook

Online Textbook (OpenStax) Reading: 

Homework: 

  • Work on test corrections.  Due before the end of the quarter, but sooner is better, because you'll need the knowledge.
  • Reading, above, is optional.
Class 7 Tuesday, 9/19/17

Warm Up :   None

Today:  Test -- 1-D Kinematics

Online Textbook (OpenStax) Reading: 

Homework: 

  • None.  Reading, above, is optional.
Class 6.5 Monday, 9/17/17

Warm Up : (Ignore air resistance for all questions)

Suppose a plane is flying at a constant elevation of 500m and the pilot is trying to drop a bomb on a target on the ground. 

1.  Assuming g=10m/s2, how long will it take the bombs to reach the ground?

2. If the  plane is flying with a speed (relative to the ground) of 200m/s, how far in advance should be bomb be released?

3.  For an observer watching the plane from our perspective, what is the shape of the bomb's flight path?

4.  What is the bomb's acceleration in the X dimension?  What about the Y dimension?

Today:

Homework: 

  • Study for the test (see last class, below, for details)
Class 6 Friday, 9/15/17

Warm Up:

A race car is traveling counterclockwise around a circular track.  The car's speedometer stays on exactly 100mph the whole time.

Describe what happens to each of the following as the car makes one revolution around the track:  

a)  the car's speed   b) the car's velocity  c) the car's acceleration.

 

Today:

  • Watch and discuss some videos  (B3/4  B5/6). 
  • A final practice test.  1-D Kinematics Practice Test #2Solutions
  • Actual test format:
    • 2 short answer -- describe a motion having ____ acceleration and ____ velocity (1 point each)
    • 10-15 multiple choice (1 point each)
    • 4-6 problems (4 points each)
    • 1 Unit conversion Problem (2 points)
    • 1 Extended problem with 4-6 parts (2 points for each part)
    • Each problem will be similar in structure (though not in details) to some other problem that has already been assigned.
    • The test will look like a hybrid of  1-D Kinematics Practice (Mr. Pennington's old test) and 1-D Kinematics Practice Test #2

Online Textbook (OpenStax) Reading: 

Homework: 

  • Study for the test.  Review old problems.  Come to class ready to ask questions.
Image result for pneumatic potato cannonClass 5.5 Thursday, 9/14/17

Warm Up:

This potato cannon accelerates a potato with air compressed air.  How much faster will the potato travel if the barrel is extended to twice the current length?  Assume that there is no friction and that the air pressure pushing the potato is constant and equal in both cases.

a.  Same speed     b. Faster, but not twice as fast    c.  Twice as fast    d. More than twice as fast

Today:

Online Textbook (OpenStax) Reading: 

Homework: 

Image result for celebratory gunfireClass 5 Wednesday, 9/13/17

Warm Up:

Sometimes people celebrate special occasions by firing guns into the air. 

1.  Is this ever a good way to celebrate?  Explain.

2.  What if the bullets were grapes?  What about other healthy snacks?

3.  What factors influence the terminal velocity of a bullet (or a snack)?

Calculated terminal velocities of various spheres.

Today:

Online Textbook (OpenStax) Reading: 

Homework: 

Image result for long exposureClass 4.5 Tuesday, 9/12/17

Warm Up:

Suppose we strap a light source to a bike tire and then roll the tire to the right while taking a long-exposure photograph through several rotations of the tire. 

1.  Describe the appearance of the photograph.

2.  In the X dimension, what would graphs of position, velocity, and acceleration look like for the light source?

Today:

Online Textbook (OpenStax) Reading: 

Homework: 

Class 4 Monday, 9/11/17

Warm Up:

Match each position vs. time graph with the correct velocity and acceleration graph.

Today:

Online Textbook (OpenStax) Reading: 

Homework: 

Class 3.5 Friday, 9/8/17

Warm Up:

The symbol "g" usually represents the absolute value of the acceleration of gravity near Earth's surface.  The approximatevalue of g is 9.8m/s2, but for the following problem, assume it is 10m/s2...

Given g =10m/s2, what would the velocity and acceleration graphs look like for an object that is initially flying directly upward at a speed of 20m/s? [Ignore air resistance.]

Today:

  • How to perform video analysis method 2.
  • Work on Motion Video Scavenger Hunt 
    • Create Videos
    • Transfer videos to a school computer.  Name them something descriptive and helpful.
    • Upload Videos to Google Drive
    • Set your shared settings so that anyone in the district can view the videos.
    • Share the videos with your group, or send them links.
    • Individual Work:
      • Choose two videos to analyze.  One must use the stationary camera method, and one must use the moving camera method.
      • Click one of these links to your class spreadsheet -- B3/4B5/6
      • Enter your name on the next open row.   Insert links to your videos into columns C and G.  Enter descriptions of what the video is supposed to demonstrate into columns B and F.
      • Video Analysis Directions
      • Analyze one video using Logger Pro (stationary camera with reference object in the video) and analyze another video without using QuickTime (motion along a ruler).  To make your task easier, feel free to copy these spreadsheetsand modify them to meet your needs (Logger Pro method, Quicktime Method).

Online Textbook (OpenStax) Reading: 

Homework: 

  • Complete 1-D Kinematics Practice Answer Key (one of Mr. Pennington's old tests) by the beginning of class on Tuesday. Answers to problems: 1) 26.4m/s  2) 8.69x10^4km/h  3) 7.67x10^-8s  4) 58.5m  5) 28.8m/s  6) 12.2s  7) 10.8m/s
  • You will have more time next class to complete the video analyses.

 

Weight falling from windowClass 3 Thursday, 9/7/17

Warm Up:

How can the video on the right be used to determine the acceleration of gravity?

Today:

  • Check/review homework -- measure/calculate/estimate the acceleration of gravity using this video.
  • Motion Video Scavenger Hunt 
    • Create Videos
    • Transfer videos to a school computer.  Name them something descriptive and helpful.
    • Upload Videos to Google Drive
    • Set your shared settings so that anyone in the district can view the videos.
    • Share the videos with your group, or send them links.
    • Individual Work:
      • Choose two videos to analyze.  One must use the stationary camera method, and one must use the moving camera method.
      • Click one of these links to your class spreadsheet -- B3/4B5/6
      • Enter your name on the next open row.   Insert links to your videos into columns C and G.  Enter descriptions of what the video is supposed to demonstrate into columns B and F.
      • Video Analysis Directions
      • Analyze one video using Logger Pro (stationary camera with reference object in the video) and analyze another video without using QuickTime (motion along a ruler).  To make your task easier, feel free to copy these spreadsheetsand modify them to meet your needs (Logger Pro method, Quicktime Method).

Online Textbook (OpenStax) Reading: 

Homework:

1.  None.  You will have today and tomorrow to work on this video analysis.  It is possible that you may have to put in some time outside of class, so try to get the Logger Pro work done in class.  Most students will have no problem accessing quicktime and Google Sheets at home, but you won't have Logger Pro.

Class 2.5 Wednesday, 9/6/17

Warm Up:

1. For letter a, on the right describe what an object could be doing in order to have both positive velocity and positive acceleration.

2.  Do the same for the rest of the letters.

Today:

  • Enter attendance
  • Check/review homework --  Answer Key -- Kinematics Formulas and Practice Problems
  • Motion Video Scavenger Hunt 
    • Create Videos
    • Transfer videos to a school computer.  Name them something descriptive and helpful.
    • Upload Videos to Google Drive
    • Set your shared settings so that anyone in the district can view the videos.
    • Share the videos with your group, or send them links.
    • Individual Work:
      • Choose two videos to analyze.  One must use the stationary camera method, and one must use the moving camera method.
      • Click one of these links to your class spreadsheet -- B3/4B5/6
      • Enter your name on the next open row.   Insert links to your videos into columns C and G.  Enter descriptions of what the video is supposed to demonstrate into columns B and F.
      • Next class you will be using Logger Pro and Google Sheets to create graphs of position vs. time and velocity vs. time for your videos.

Online Textbook (OpenStax) Reading: 

Homework:

1.  Find a way to measure/calculate/estimate the acceleration of gravity using this video.  Try to find a solution that does not involve logger pro.  With a little ingenuity, you can arrive at a decent answer from any computer with internet access.  Remember that you can see greater detail if you download the video and watch it using Quicktime.  Show your work and be prepared to show/explain your methods to the class. 

2.  Complete as much of the motion video scavenger hunt work as you can before next class.

Class 2 Tuesday, 9/5/17

Warm Up:

Assuming that the man in the picture is 2m tall, and the frame rate of the camera was 10frames per second, what were the approximate maximum and minimum speeds of the object?

Today:

Online Textbook (OpenStax) Reading: 

Homework:

Class 1.5 Friday, 9/1/17

Warm Up:

A runner sprints exactly 100m, rests for a moment, and then slowly follows the same path back to the starting line.  This entire trip takes 200s.  For the questions below, consider the runner's entire round trip.

1.  What distance did the runner travel?
2.  What was the runner's displacement?
3.  What was the runner's average velocity?
4.  What was the runner's average speed?

Today:

Online Textbook (OpenStax) Reading: 

Homework:

Class 1 Thursday, 8/31/17

Warm Up:

Each lettered curve on the right represents the position(s) of a person over a time span of 10 seconds.

For this graph, position is the distance to the right of the origin (a.k.a. the zero meter mark)

For each letter, describe the person's motion (or lack of it) during the 10 seconds represented on the graph. 

 

Today:

Handouts:

Online Textbook (OpenStax) Reading: 

Homework:

Class 0.5

Wednesday, 8/30/17

Physics 200: Mr. Stapleton

Warm Up:

Spin one of the "sprotating cylinders" by pressing one end until it squirts out from under your finger.  Try pressing the other end.

When the cylinder is spinning, why do you only see the symbol that you press?

Slow motion

Today:

  • Learn names/pronunciations
  • Enter attendance
  • Student info sheet
  • Mr. Stapleton background, philosophy, slideshow, etc.
  • Go over course expectations, class overview (see last year's site)
  • First Unit:  Motion in 1 Dimension -- position, displacement, velocity, acceleration, etc.
  • Questions?
  • Start Motion Matching Activity together  Matching Motion Graphs with motion detector (Web page) 
  • ***B5/6 has D lunch.

Handouts:

Online Textbook (OpenStax) Reading: 

Homework:

  • Get your course expectations signed and then return them.
  • Suggested Reading (see above)