Class 43.5 Friday, 1/21/22

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: 

Homework: 

  • None
Class 43 Thursday, 1/20/22

Warm Up:  Let's actually solve the warm-up problem from yesterday.

Today: 

Homework: 

Class 42.5 Wednesday, 1/19/22

Warm Up:  When the two blocks collide, they stick together.  What is the shared velocity of the two blocks after the collision?

Today: 

  • Donuts
  • Exams
    • Take a look -- don't forget to return
    • Score distribution before adding 3.5 points

Homework: 

  • None
Class 41.5 Friday, 1/7/22

Warm Up:  A student wants to launch a pencil as far as possible using energy stored in exactly two rubber bands.  The sharpened pencil has fins on its eraser end and a protruding paper clip attached near the nose.  The pencil is to be launched by a looped string that connects to the paper clip on one end and the rubber bands on the other.  If the teacher has placed a limit on the total amount of force that can be used in launching process, would any one of these configurations be better than the others?  Explain.

Today: 

  • Last minute exam questions?
  • Disassemble trebuchets.  If you really and truly want to keep yours, you can keep it.
  • Trebuchet slides are due at midnight -- for contest purposes.  You can turn it in later, but that may be too late for the contest.

Homework: 

  • Exam review
Class 41 Thursday, 1/6/22

Warm Up:  None

Today: 

  • Midterm review --
    • **The formula list in Google Classroom has been updated**
    • Updated Google Doc with notes from this week's classes -- In-Class Midterm Review
    • Back to Kinematics in 2-D -- Range Formula
    • Finish forces
      • Problems with Forces and kinematics
      • Specific Tools needed to solve force problems
        • Weight
        • Tension/Normal Force/Contact Force
        • Friction
      • 2-D force problems
        • Static problems
        • Blocks, pulleys, and ramps
    • Energy -- take a look at the formulas on the formula sheet
  • Project work time

Homework: 

  • Exam prep
Class 40.5 Wednesday, 1/5/22

Warm Up:  What is an algorithm?

Today: 

Homework: 

  • Exam prep
Class 40 Tuesday, 1/4/22

Warm Up: 

1.  List all of the variables that show up in kinematics problems. 

2.  List all of the kinematics formulas. 

3.  In projectile motion problems, which

Today: 

  • "Notes sheet" options. 
    • Option 1: You can hand-write (or draw) anything you want on both sides of an 8.5"x11" sheet of paper, and use that paper on the exam.  You, personally, must make your own notes sheet.  You must turn in your notes sheet with your exam.
    • Option 2:  You can opt out of the notes sheet and recieve an extra 2% on your exam grade.
    • Not an option: using a formula sheet that I provide.  If you want the formulas, put them on your notes sheet.
  • Midterm review -- Kinematics (1D and 2D)?
    • Questions about the multiple choice review material?
    • Problem Solving (work through example problems) -- Necessary information and algorithm
      • Givens -- stated and implied
      • Trig functions and inverse functions, Pythagorean Theorem
      • Manipulating Vectors -- adding, subtracting, and resolving
      • River problems
        • Identifying components and resultant
        • Solving
      • Projectiles
        • Vertical motion only -- "free-fall"
        • 2-dimensional motion

Homework: 

  • Study.  Make a notes sheet -- at least write down the formulas, even if you don't plan to use the sheet on the exam.  Instead of copying specific problems, write down problem-solving processes (algorithms).
Class 39.5 Monday, 1/3/22

Warm Up:  1.  How would you find the efficiency of this trebuchet?

2.  How can you find the center of mass of an irregularly shaped object like the one below?

 

Today:  Determine your trebuchet's efficiency.  Make a slideshow (like this one) showing your process.

  1. Energy Input:
    1. Determine the amount of potential energy that is lost by your trebuchet as it launches.  Use the same method that I used in slide 2 of my slideshow.
    2. Create slide 2 of your slideshow.  Include two photos illustrating the change in position of the center of mass of the falling components.
  2. Energy Output:  On a desktop or laptop...
    1. Find your video in this Google Drive folder -- The dividing line between 5/6 and 7/8 is somewhere around file number 250.  Note that most file names include an E, but some don't.
    2. Download your video.
    3. Open the Vernier Video Analysis App, and insert your video.
    4. Click "System" and "scale," and then stretch the scale tool to known points on the meter stick in the video.  Enter this distance in meters.
    5. Use the "add" tool to click on the positions of the projectile just before it is launched.  If it's blurry, I find it easiest to click on the front of the blur.
    6. Take a screenshot of your projectile and the blue dots from the vernier app, and paste this into your slideshow on page 3.
    7. Calculate the projectile speed:
      1. Select the Xvelocity and Yvelocity data for these points.  Copy the data.
      2. Open a spreadsheet, and paste the data.
      3. Next to the X and Y velocity columns, create a new column that calculates speed.  You should know how to do this, but ask if you need help.
      4. To determine your projectile's actual speed, you can average the speeds, or you can use the one that you think is probably correct.  Highlight (or make bold) the speed that you are going to use.
      5. Take a screenshot of your spreadsheet calculations, and paste that into your slideshow on page 3.
  3. Efficiency.  On slide 4, show your efficiency calculations.

Homework: 

  • Review the midterm study guide.  If you have questions, write them down and ask them in class or via email.
Class 39 Wednesday, 12/22/21

Warm Up:  Some cultures celebrate a character called Santa Claus, who delivers presents around the world in a sleigh.  This event occurs over a time interval known as Christmas Eve.  If Santa were to deliver a present to every child who believes in him, how fast would Santa need to accelerate between stops in order to deliver all of the presents on Christmas Eve? Santa Claus from an Engineer's Perspective

Today:

  • All of the Midterm Exam review stuff is now in Google Classroom.  The only thing I haven't provided is answers to the multiple choice.  Those answers will be available later.  Try the questions first.  You can email me when you want the answers.

  • Trebuchet Contest Day Procedure...

    1. Preserve your trebuchet!  After you launch, store it in a safe place, and do not dismantle it.  We won't have time today to find the trebuchets' centers of mass (which we need in order to calculate input energy, and, thus, efficiency).

    2. Record the mass of your projectile + sling.  It should be at least 3 grams.  If it's over weight, you can trim it down with scissors, but it's not clear that this will make a positive difference.

    3. Record the overall mass of your trebuchet (everything but the projectile and sling).

    4. Record the highest height reached by any part of your trebuchet, during the throw.  Do not include the projectile, sling (fishing line), or finger.

    5. Have Mr. Stapleton video your trebuchet throwing its projectile.  This video will be used to determine energy input and energy output.

    6. Have Mr. Stapleton confirm and record your throwing distance.

    7. Enter today's data in this form, so that we can compare preliminary standings.  Bear in mind that overall scores depend on both distance and efficiency.

    8. Store your trebuchet carefully, so that you can finish the analysis after break.

Homework: 

  • Review the midterm study guide.  If you have questions, write them down and be prepared to ask them after break.
Class 38.5 Tuesday, 12/21/21

Warm Up:  Let's discuss the Midterm.

Today:

  • Midterm Exam Information (It's all in Google Classroom)

    • Weight:  20% of Semester 1 Grade

    • Format:  100 Total Points -- 25 Multiple Choice (1 point each), 15 Problems (5 points each)

    • Problem Distribution:

      • 1-D Kinematics (3)

      • 2-D Kinematics (4)

      • 1-D Newton's Laws (3)

      • 2-D Newton's Laws (2)

      • Work and Energy (3)

    • More Problem Information

    • Provided Formulas: 

    • Practice Material:

    • Links to videos explaining problem solutions are available in Google Classroom.  In fact, everything is in Google Classroom!

  • Work time. 

Homework: 

  • Optional -- Exam review.  If you complete the multiple choice questions over break, and you want to see my answers before we return to school, email me your request and picture(s) your answers.  I won't be checking my email very often, but if I see your request and answers, I will share my answers with you.  If you have questions about the multiple choice, you may also email me your questions.
Class 38 Monday, 12/20/21

Warm Up:  None

Today:

  • Optional Test Retake

  • Work time -- as quietly as you can

Homework: 

  • None
Class 37.5 Friday, 12/17/21

Warm Up:  

1. How does a hydraulic lift facilitate work with a small input force and a large output force?

2.  How do gears work in a car with a manual transmission?  gearbox-diagram.gif (825×585)How Manual Car Gears Work » Learn Driving Tips

Today:

  • Work time. 

Homework: 

  • None
Class 37 Thursday, 12/16/21

Warm Up:  

1.  What is the point of having a variety of gears on a bicycle? (or a car, motorcycle, etc.)

2.  Why is this effective?

Today:

  • Note one more addition to the trebuchet scoring process, dealing with trebuchets that exceed the 0.7J input energy limit.

  • Work time. 

Homework: 

  • None
Class 36.5 Wednesday, 12/15/21

Warm Up:  Click this link and answer the trebuchet question for our Physics PLC.

Today:

  • Return tests.

  • Trebuchet work time

Homework: 

  • None
Class 36 Tuesday, 12/14/21

Warm Up:  None

Today:

  • Test over work and energy

Homework: 

  • None
Class 35.5 Monday, 12/13/21

Warm Up:  

1.  Which arm ( shown in yellow, in figure 1) will wobble the least on the axle?  Why?

2.  Which arm (figure 2) will experience the least friction as it rotates? Why?

3.  Which arm (figure 3) is least likely to bend the axle?  Why?

Whic

Today:

  • Work time.  Build your trebuchet

  • Questions about the test?

Homework: 

  • Test tomorrow
Class 35.5 Friday, 12/10/21

Warm Up:  

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

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

3.  Why?

Slinky drop

Slinky drop answer

1st Video

Slinky drop with tennis ball

Supersized Slinky

 

Today:

Homework: 

  • Test on Tuesday.
  • Be ready to start building your trebuchet on Monday.
Class 34.5 Thursday, 12/9/21

Warm Up:  How could we measure the efficiency of this trebuchet?

 

Today:

  • Check/review homework 

  • Mr. Pennington's "4 Minute Drill" on page 16.  Answers

Homework: 

Class 34 Wednesday, 12/8/21

Warm Up:  

1.  A lightweight object and a very heavy object are sliding with equal speeds along a

level frictionless surface. They both slide up the same frictionless hill.

Which rises to a greater height before coming to rest?

       A) The lightweight object, because it weighs less.

       B) They both slide to the same height.

       C) The heavy object, because it has greater kinetic energy.

       D) Cannot be determined from the information given.

2.  A car and a truck are driving on snow at the same speed and with tires having the same

coefficient of kinetic friction.  They both lock their brakes and skid to a stop on level ground.  If the truck has 2x the

mass of the car, how do their stopping distances compare?

       A) The car slides farther.

       B) The truck slides farther.

       C)  Their sliding distance is equal.

      D) Cannot be determined from the information given

 

Today:

Homework:  Complete the problem section of Mr. Pennington's 2015-2016 Test on p. 14-15 of the packet.  Solutions

Image result for wedge mechanical advantageImage result for hockey stick fulcrumImage result for boat winchClass 33.5 Tuesday, 12/7/21

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?  If you don't have a quick answer to this, move on to the other questions and come back to this one.

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:

  • Check/review homework 

Homework:  Complete the multiple choice section of Mr. Pennington's 2015-2016 Test on p. 11-13 of the packet.  Solutions

Class 33 Monday, 12/6/21

Warm Up:  Suppose I hang a spring from the ceiling.  I then hook a 200g mass to the bottom end of the spring and let go.  The mass falls and bobs up and down until it finally comes to rest.  The spring's constant is k = 4N/m.

1.  Does the spring have more total energy at its low point or at its final resting point?

2.  How much work is done by friction during the time the weight is bobbing?

 

Today:

Homework:  Complete the rest of packet p.9-10 (#4-11, "More work and energy practice problems")  solutions  Video explanations

Class 32.5 Friday, 12/3/21

Warm Up:  Assuming that all three bows are drawn to a distance of 0.5m...

1.  Which bow stores the most energy when it is drawn to this distance?

2.  Estimate the energy stored in each bow.

Today:

  • Presentation of Water Rocket Prizes (during 7/8)

  • Check/review homework

  •  Springs notes (packet page 8)  Notes key

Homework:  Two parts!

  1. Complete page 6 (#2 of the practice quiz)  of the packet  Solutions    Video Solutions
  2. #1-3 on page 9 (More Work and Energy Practice Problems)  solutions  Problem #3 clarification
Class 32 Thursday, 12/2/21

Warm Up:  

1.  Can you guess what the "sisyphus train" does?

2.  How did it get that nickname?

 

Today:

  • Return stuff -- including tests

  • Test Retakes:  I will reserve at least 30 minutes at the end of class next Monday and Wednesday, for retakes.  I won't be putting solution videos in Google Classroom, because I think all of the necessary explanation is provided in the homework section of class 30, below.  I did put the answers and solutions in Google Classroom, in the form of a spreadsheet.

  • In case you're wondering how all of the tests and projects are being weighted, here's my spreadsheet.

  • Unit 5 Packet -- Work and Energy  PDF Version

  • Finish the notes on conservation of mechanical energy (pages 2-3)

  • Together, work on #6 on page 4. Here's a video explaining #6.

  • Begin the homework

Homework:  Complete page 5  of the packet Solutions  Video for problem 1  (#1 of the practice quiz)

Class 31.5 Wednesday, 12/1/21

Warm Up:  What will happen to kinetic energy, potential energy, thermal energy, and total energy of the skateboarder during a ride in the half pipe?  A) with zero friction  B) with a lot of friction

Today:

Homework:  None

Class 31 Tuesday, 11/30/21

Warm Up:  No warm up -- test today

Today:

  • Test

  • Start on the homework, if you haven't done it already.

Homework:

  • Check last night's homework using the answers below.  If you missed any of them, watch the corresponding part of this video, where I explain my solutions.  We will not go over the homework in class (unless you watched the video and still have questions).

  • Homework answers: 1a. 40J   1b. 400W   1c.   21.7m/s   2a.161,040J   2b. 0.49 Snickers   3a.17.8N   3b. 535J   3c.17.7m/s   4. 0.67hp   5a. 604,747J   5b. 201,582W   5c. 270hp   5d. 43.8   5f. 65.7m

  • Here are links to the written solutions shown in the video...

  •  

Class 30.5 Monday, 11/29/21

Warm Up:  Do you know how to make a cloud in a 2-liter bottle, using water and a small amount of smoke?  Can you explain it in terms of work and energy?

Today:

Homework:

Class 30 Friday, 11/19/21

Warm Up:  None

Today:

  • Note -- There was a mistake on problem #2, on page 11 of the packet.  I meant to change the coefficient of friction to 0.1.  At 0.3, the system does not accelerate.

  • Take tests/retakes

  • Work time

Homework:

Class 29.5 Thursday, 11/18/21

Warm Up:  Why does tension show up so often in physics problems?  Is tension overrated and overrepresented?

Today:

  • Check/discuss homework

  • Does anyone want to start on the Unit 4 test today?

Homework:

Class 29 Wednesday, 11/17/21

Warm Up:  

A waiter is delivering a chunk of bone, basted in synovial fluid, to some dinner guests.   Touching only the serving tray (also made of bone), the waiter must deliver the dinner bone to the guests, and place it carefully on their table.  Assuming the guests' table is to our left in the picture, describe what the waiter would need to do in order to make this happen?  Can you sketch the forces on the bone using the head-to-tail method? [Let's just assume that the bone is frictionless.]

Today:

  • Return stuff

  • Check/discuss the homework

  • (Unit 4 Packet PDF version)

  • Do problem #3 on page 6 of the packet.  Solutions to 1-4 on p 5 and 6

  • Work time -- practice test.

  • If you want to try to take this test early, tomorrow and/or on Friday, you can do that and still have the opportunity to take and retake the test after break.  I should be able to grade it quickly and get it right back to you.

Homework:

Class 28.5 Tuesday, 11/16/21

Warm Up:  

1. Cheryl wants to use some string and a nail to hang a treasured portrait of great-great-grandfather Ernesto as a young man.  The portrait is rather heavy.  Rank the three configurations on the right according to their risk of exceeding the breaking strength of the string.

2. How are static equilibrium and dynamic equilibrium different in physics problems?

 

Today:

Homework:

  • Complete # 2 from page 5 of the  packet.  Solutions

  • If you want to re-submit your project sheets, do so by the Tuesday after break

Class 28 Monday, 11/15/21

Warm Up:  

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

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

2.  How can we find the tension in the string?

3.  How can we describe the motions of the mass and the train car in quantitative terms.

Today:

  • Turn in project sheets -- one set per group.  All names at the top.

  • Test grade distribution

  • Get the Unit 4 Packet PDF version.  Number the pages (I forgot).

  • Notes -- Bodies on Inclines (packet p 1) -- Video from last year

  • Do another example problem (like #2 from the packet)

Homework:

Class 27.5 Friday, 11/12/21

Warm Up:  One end of a rope is attached to the Gladys' belt.  Gladys is pulling directly downward on the other end. Assuming that the pulley and rope are massless and fictionless, how much downward force must Gladys apply in order to ascend?  Gladys weighs 500N.

Today:

  • Return tests

  • finish the project sheets.

Homework:

  • Project sheets are due on Monday.  One per group.

  • The optional test retake day is next Friday.

Class 27 Thursday, 11/11/21

Warm Up:  None

Today:

  • Test -- Newton's Laws in 1-D

  • You CAN have time tomorrow to finish the project sheets.

Homework:

  • Rocket analysis sheets are due on Monday (one set per group).  After your project sheets are graded and returned, your group will get one chance to correct your work and resubmit it for a better grade.

  • The optional test retake day is next Friday.

Class 26.5 Wednesday, 11/10/21

Warm Up:  The 50kg rower in the photo is accelerating at a rate of -1m/s2.  She is pulling against the oars with a force of 100N. Calculate and show all of the forces acting on the rower.

Today:

  • Project work time

Homework:

  • Test Tomorrow

  • Rocket analysis sheets are due on Monday (one set per group).  After your project sheets are graded and returned, your group will get one chance to correct your work and resubmit it for a better grade.

Class 26 Tuesday, 11/9/21

Warm Up:   This is a graph of one group's "pressure altitude" data.  The graph shows altitude vs "elapsed seconds."  What do you notice?  Can you explain any of its oddities?

Today:

  • If you didn't finish the video analysis yesterday, finish it today.
  • As soon as you find your rocket's time aloft, enter it (along with the file name of your video in the Google Drive folder) into this form.
  • Complete part 2 of the rocket analysis  PDF version
  • If you want to use my correction spreadsheet for #13 and/or #14, here it is.
  • You can have project work time today and tomorrow, but we will be starting something new on Friday.  The rocket analyses are due on Monday.  Turn in one set of sheets of paper as a group. 
  • Test on Thursday.

Homework:

  • Rocket analysis sheets are due on Monday (one set per group).  After your project sheets are graded and returned, your group will get one chance to correct your work and resubmit it for a better grade.

  • Test on Thursday -- see class #25 homework for more study materials

Class 25.5 Monday, 11/8/21

Warm Up:   How many water bottles are used to launch this game show contestant?  Is this for real?

 

Today:

Homework:

  • Work on video analysis calculations.  Compare answers with your group tomorrow.

  • Test on Thursday!

Class 25 Friday, 11/5/21

Warm Up:   None -- rocket launch

Today:

  • Prepare for launching.
    1. Record your rocket's 1) dry mass with sensor and foam, 2) added water volume,  3) overall length
    2. Add water -- carefully.  Pour very slowly from a graduated cylinder.  Clifford Heath's  Water rocket simulator -- seems to underestimate the performance of heavier rockets, but seems to be a good indicator of the best water volume to use.
    3. Optional Sensor Data Collection Plan...
      • Don't put your sensor in your rocket until you're almost ready to launch.  We will have duct tape outside to close up your rocket.
      • Do pay attention to the name on your probe.
      • When you insert the probe, make sure that the button is not getting pressed.  Also, insert it with the positive Z axis facing up (like the picture from yesterday).
      • Once your rocket is on the launcher, remind me to put your rocket in memory data mode.
        • I will connect and confirm that the sensor is collecting data
        • I will start the data logging from my phone.
        • As soon as your rocket lands, bring it to me so that I can stop the data logging. 
        • At this poin turn off the probe to save battery life (hold the button until the LED glows solid red)
      • When you are back in the classroom, connect to the sensor, go to data memory mode, and download the data. BE CAREFUL!!! DO NOT BE A FAST, CRAZY CLICKER or you may clear the data before you realize what you've clicked.  Finally, upload the data to your Google drive and share with your team.
    4. After the launch, clean up the room.  B7/8, please help with the process of packing up the launcher, hoses, and power cord.
    5. If we have time, disassemble your rocket (unless you want to keep it).  Recycle what you can (plastic bottle pieces with no tape and little or no glue).  Return reusable materials (e.g. lead weights, foam, caps, and sensors).  Duct tape, hot glue, and CD parts go in the trash.

Homework:

Class 24.5 Thursday, 11/4/21

Warm Up:   The graph on the right shows the current acceleration data for the PocketLab sensor sitting motionless on my desk.  The positive Z axis (green) extends "perpendicularly" out of my desk surface.  The positive X axis (orange) extends rightward from the sensor.  The positive Y (purple) axis extends away from the camera, parallel to the desk surface.

 

Why are the X and Y axes showing a constant acceleration near 0m/s^2, while the Z axis shows a constant acceleration of around positive 1g?

 

Today:

  • Rocket Project Overview
    • Goal:  Make a rocket that...
      •  flies as high as possible (prize for the highest flyer(s))
      • Allows us to collect data that we can analyze in order to determine the following:
        • Average force of water thrust
        • Time interval of thrust
        • max height
        • drag coefficient
        • and more
    • Data we will collect and analyze
      • Rocket Measurements (Water volume, dry mass, length)
      • Slow motion video
      • Pocketlab Probe Data
        • "Pressure Altitude"
        • "Acceleration"
    • Grading will be based on your analysis of the data, not on rocket success.  You will need to have data to analyze, so your rocket needs to go up straight and come down straight. 
  • Quick demo showing how to collect and save PocketLab probe data in "memory mode." 
  • Finish rocket construction and prepare for tomorrow's launch.
  • Practice collecting data with the probe.  Connect to a probe and insert it into one of our pieces of foam.  Then drop it from the hallway window and record "Acceleration" and "Pressure Altitude" data.  Directions are in this Google Doc -- (pocketlab data collection directions).  Be ready to do this tomorrow when we launch your rocket.  The most important data will be the "Pressure Altitude" data.  If the sensor has less than 50% charge, please charge it.  If you want to compare your data with the real drop distance, the height of the windowsill above the ground outside is approximately 4.5m.
  • PocketLab App Link
  • Record these measurements before tomorrow's launch: 
    • Rocket total dry mass.  This includes everything but the water (rocket, foam, probe, etc)
    • Added water volume.
    • Rocket overall length

Homework:

  • On your own, it would be a good idea to review the packet for next Thursday's test.

Class 24Wednesday, 11/3/21

Warm Up:   No warm-up today.  Make rockets.

 

Today:

  • 7/8 -- we never went over the homework yesterday.  Does anyone have questions?
  • Rocket construction -- important info
    • Design your rocket with recyclability/reusability in mind.  You will have to disassemble it  and sort the parts when we're done.
    • Torch safety:
      • Be aware of objects beyond the end of the torch!
      • Catch all smoke with the fume extractor
      • The nail may still be hot even if it is not glowing red
    • Lead Weights
      • Wash your hands after handling
      • Weights should have a support behind them, in order to prevent their ripping loose during intial acceleration.
    • New group requirement -- no 1 person groups; we need larger groups (at least pairs) to reduct the number of probes that are required.
    • Cutting bottles -- how to start
    • Glue sticks -- location and another warning
    • Duct taping
    • Conserve cardboard.  Cut from a piece that has already been used -- until that piece is used up. 
  • If you're not doing anything else today, you could ractice with a pocketlab probe.  Directions are in this Google Doc -- (pocketlab data collection directions).

Homework:

  • On your own, it would be a good idea to review the packet for next Thursday's test.

Class 23.5 Tuesday, 11/2/21

Warm Up:  [Video link for absent students]The diagram on the right shows a typical water rocket.  Mass has been added to the tip of the rocket, and fins have been added to the back (bottom).  There is a requisite 10cm long section dedicated to holding foam for protecting the probe.

1.  What makes the rocket move upward?

2.  Why do fins need to be added to the back of the rocket?  How does this work?

3.  Why does mass needed to be added to the front of the rocket?  How does this work?

4.  Aside from stability, what other reason is there for adding mass to the rocket?

 

Today:

  • Check/review homework -- I forgot to do this in 7/8!
  • Discuss important rocket design characteristics.  Rocket Guidelines/restrictions
  • Brief rocket planning -- if you want to bring extra materials, assign responsibility
    • Clifford Heath's  Water rocket simulator -- seems to underestimate the performance of heavier rockets, but seems to be a good indicator of the best water volume to use.

Homework:

  • On your own, it would be a good idea to review the packet for next Thursday's test.

Class 23 Monday, 11/1/21

Warm Up:  

Starting from rest, a car in the real world (which includes air) accelerates to its maximum speed, maintains that speed for a few seconds, and then brakes as rapidly as possible.  Draw a series of four force diagrams to show how the net force and the individual forces acting on the car change over time.   Use labeled arrows to show all of the forces (and the net force) acting on the car during each of these time periods.  Draw a diagram for...

1.  The car at rest

2.  The car undergoing initial acceleration

3.  The car at maximum velocity

4.  The car braking

Today:

  • Check/review homework
  • Work Time -- spreadsheet, then practice test

Homework:

  • Complete the rest (p. 26-27) of the practice test in the Unit 3 Packet    answers

  • Finish and submit your spreadsheet and use it to solve this problem...

    • A water rocket has a cross-sectional area of 0.01m and a mass of 0.15kg.  After flying directly upward to a height of 80m, the rocket falls directly downward for exactly 5 seconds before hitting the ground.  If the density of the air in the launch area is 1.22kg/m^3...

      • What is the rocket's drag coefficient?

      • What is the rocket's speed when it hits the ground?

Class 22.5 Friday, 10/29/21

Warm Up:  

1. Which can you throw with more force, a Wiffle Ball® (0.045kg), a baseball (0.145kg), or a shot put (5.45kg)?  Or is there no difference?  Explain your thinking. Some calculations -- don't peek before thinking.

2. What limits the amount of force that you can apply when you throw an object?

Interesting Link:  article about the fastest pitch ever thrown

 

Today:

  • Check/review homework
  • Work Time -- Trajectory with Drag Spreadsheet or homework
  • Deadline change -- spreadsheet is due at midnight on Monday.

Homework:

Class 22 Thursday, 10/28/21

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?

3.  What would happen if you were standing on a bathroom scale in a motionless elevator, and then the elevator suddenly began to accelerate downward at 1g?

4.  What is the source of the "butterflies in the stomach" when we fall?

 

Today:

  • Check/review homework
  • Project Overview
    • Design an air pressure-powered water rocket that will fly as high as possible while safely carrying an electronic air pressure probe.  The flight must be controlled (cross-sectional area should be constant) and vertical.
    • Fine-tune a method to collect data that will allow you to do the following:
      • Create a graph of height vs time
      • Calculate the average force of water thrust
    • Use your data and a mathematical model (spreadsheet -- here's my example -- not shared) to determine your rocket's drag coefficient.
    • Calculate (with reasonable accuracy) the number of bottles (similar to your rocket's fuselage) that would be required to launch your body to a height of 10m.  Also calculate the acceleration you would experience.
    • This will be a group project, but parts will be completed individually.
  • Begin work on the mathematical model.  You will be using this for more than just the project, so you must complete your own, individually.
    • Make a copy of this template -- Trajectory With Drag Spreadsheet Template
    • Follow these directions...
    • As you proceed, verify your formulas with these "Solutions" -- which assume that you leave the originally-provided values in the yellow cells

Homework:

Class 21.5 Wednesday, 10/27/21

Warm Up:  

How fast does chalk fall? My spreadsheet answer

Today:

  • Check/review homework

Homework:

Class 21 Tuesday, 10/26/21

Warm Up:  

A parachuter steps out of a plane.  The total mass of the parachuter and gear is 100kg.  After falling for a while, the parachuter reaches a terminal velocity of -55m/s.  A short time later, the parachuter pulls the chute cord and reaches a new terminal velocity of -3m/s.  From that point in time, the parachuter continues to drift to the ground.

Fill out the missing data in the table on packet page 15...

 

Today:

  • Check/review homework
  • Finish the notes -- graph on packet page 14
  • Work Time -- see assignment below

Homework:

Image result for cat falling from buildingClass 20.5 Monday, 10/25/21

Warm Up:  

According to this article, 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. What's going on?

2. What's the rule for deciding whether to use "less" or "fewer?"  Which applies here?

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

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

5.  When does a falling cat experience maximum net force?

 

Today:

Homework:

  • Packet p. 16 -- "Conceptual Practice With Drag"

Class 20 Friday, 10/22/21

Warm Up:  

1.  Explain how a nordic skier can ski forward on level ground with parallel skis (classic style) and without using poles.

2.  Can this be done with downhill skis?  Explain.

Today:

Homework:

  • Multibody Drill A, problems 1-6, on packet pages 11-12.

Class 19.5 Thursday, 10/21/21

Warm Up:   I have a length of treated 4"x4" lumber, some large nails, a hammer, and a large rock.  How will it feel if I put the rock on my head and then have someone pound nails into the wood on top of the rock?

Today:

Homework:

  • On page 10 of the packet, finish writing net force equations for at least two more possible systems.  We will have already finished a few.

 

Class 19 Wednesday, 10/20/21

Warm Up:   None -- retake day

Today:

  • Test retakes, work time

Homework: (continued from yesterday)

Class 18.5 Tuesday, 10/19/21

Warm Up:   On level ground, Tim begins sliding with a velocity of 6m/s.  If Tim's slide lasts for 2 seconds, what is the coefficient of kinetic friction between Tim and the slide?

Today:

  • Check/review homework
  • Work time -- not enough time today for a proper introdu ction to "multibody" problems.
  • The optional retake will be next wednesday

Coming up: 

Homework: Due on Thursday!

Class 18 Monday, 10/18/21

Warm Up:   One way to find the center of mass (a.k.a. balance point) of a stick is to support it with two 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:

  • Classroom culture check-in survey
  • Check/review homework
  • Notes:  Friction (Packet page 8) Filled-in version
  • The optional retake will be next wednesday
  • Work time -- homework or re-do shot one of the launcher project.  It will be a horizontal launch at some height.  No obstacle.

Coming up: 

Homework:

Class 17.5 Friday, 10/15/21

Warm Up:   Why can't you literally "pull yourself up by your own bootstraps?"  This question has also been stated as "why can't you pick yourself up?" 

Today:

  • Return Launcher Contest Problems
  • Check/review homework
  • Notes:  Newton's 3rd Law (Packet page 7) Filled-in notes  video of notes
  • The optional retake will be next wednesday

Homework:

Class 17 Thursday, 10/14/21

Warm Up:   It is possible to remove a sheet paper from under a dry erase pen without touching or tipping the pen.  How can one do this without tipping the pen?  Why does the pen usually fall? 

Today:

Homework:

  • Conceptual #1-2 and Problems #1-6 on pages 4-5 of the Unit 3 Packet  This solution link doesn't seem to be working, so I put the solutions in Google Classroom.  Answers and Solutions
Class 16.5 Wednesday, 10/13/21

Warm Up:   There is a heavy object suspended from the ceiling by a string.  Another segment of the same string is hanging downward 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:

  • I failed to record some assignments that were due around 9/27 and 9/28.  Who did/didn't do them? (enter grades)
  • Contest Results
  • Did anyone discover any test grading mistakes?
  • Get Unit 3 Packet (Newton's Laws in 1-D)
  • The optional retake will be next wednesday.
  •  Does anyone have questions?

Homework:

  • None -- if you're planning to retake the test, use tonight to prepare.
Class 16 Tuesday, 10/12/21

Warm Up:   Get your launchers ready.  No practice shots!  Make a plan.  Once we get going, we need to achieve less than one minute per shot.  The first shooters can have a little extra time.

Today:

  • Hand in your contest problem solutions.  Make sure that all of your names are on the sheet.
  • Projectile Launcher Contest
  • Return tests.  Be aware that a few students have not finished the test.
  • Test score distribution

Homework:

  • Look over your test and see if you think there were any grading errors.  If you want clarification on a question or problem, watch the corresponding video provided in Google Classroom.  If you think there may be a grading mistake, tell me tomorrow.
Class 15.5 Thursday, 10/7/21

Warm Up:   None

Today:

  • Test, part 2 -- Projectile Problems
  • Work on the contest problems -- due next Tuesday, at the beginning of class.

Homework:

  • Solve the contest problems.  Make a plan for setting up your shots.
Class 15 Wednesday, 10/6/21

Warm Up:   None

Today:

  • Test, part 1-- Conceptual Questions and River Problems
  • Hand out the contest problems.

Homework:

  • Contest problems are due next Tuesday
Class 14.5 Tuesday, 10/5/21

Warm Up:   A boat is following a heading of 56 degrees N of E, and its speed in still water is 1.3 m/s.  Find the velocity of the river's current if the boat's actual velocity (relative to the Earth) is 3.2m/s in a direction 17 degrees W of N. Solution... Video explanation

Today:

Homework:

  • Study
  • Contest problems are due next Tuesday.  Turn in one team copy at the beginning of class and keep the other copy for your own use.
Class 14 Monday, 10/4/21

Warm Up:  Final launcher considerations...

1.  How are you going to aim your launcher in the horizontal plane?

2.  How are you going to aim your launcher in the vertical plane?

3.  How are you going to decide on your projectile's initial height? [Remember that you will be given a vertical "launch window," and it is up to you to determine the exact launch height.]

4.  How are you going to hold your launcher steady, at the height and angle of your choice?

5.  What are you going to do if you take a test shot and it turns out that your distance is off by a large amount?

Today:

Homework:

  • Test on Wednesday and Thursday
  • Do you have questions about anything on the test?  Add your question or request to this Google Doc (as early as you can -- I may not get to late submissions).  I will either create a video answering your question, or I will answer it tomorrow during class.
Class 13.5 Friday, 10/1/21

Warm Up:   Let's try out the PhET Projectile Motion Simulation and see what it has to offer.

The riverboat simulator is also interesting, but I would change the wording a bit.  Can you guess what I would change?

Today:

  • Check/review homework.
  • Final launcher practice -- set up some test shots
  • Hand out the contest problems

Other Stuff

Homework:

  • Study
Class 13 Thursday, 9/30/21

Warm Up:   What's the best way to create a graph like this one?  Exactly what do you need to do?

My spreadsheet

Today:

  • Check/review homework
  • Read over some of the details in the 2nd launcher handout.
  • Launcher calibration and practice

Homework:

Class 12.5 Wednesday, 9/29/21

Warm Up:   I like to start projectile problems by listing important variables in the X and Y dimensions (x and y components of motion).  It might also be helpful to list some resultant variables.  Let's try.

Today:

Homework:

Class 12 Tuesday, 9/28/21

Warm Up:  

1.  Based on the diagram to the right, provide definitions for precision and accuracy.  Which is easier to fix?

2.  Can you suggest some ways to improve precision?  Accuracy?

3.  What are some probable sources of error in your attempts to hit the target?

 

Today:

  • Group size limit change -- groups of 3 are now okay.  You can re-shuffle groups today.  If you want to "make a copy" of your spreadsheet and use that to create a new spreadsheet for your new group, that's okay.  However, if you were one of the group's who had a member who solved the bonus problem, we will need to discuss what makes sense in that case.
  • Get Trajectory Contest Project Handout #2  PDF Version
  • Launcher assembly, modification, data collection, and calibration graph creation.
  • Launcher Parts:    What to save in your Ziplock bag...
  • If your spreadsheet calculators don't work right now, record your calibration data anyway.  Then fix your spreadsheet and figure out the intitial velocities later.
  • Store your plunger/bands, projectile, and trigger/string in a Ziplock bag with your names and block on it.

Homework:

Class 11.5 Monday, 9/27/21

Warm Up:  

The diagram on the right shows the trajectory of a free-falling projectile that was launched horizontally.  Sketch the diagram.  Show/label the projectile's overall velocity (v), x velocity (vx), and y velocity (vy) at the start of its flight and at some other point in the flight.

Today:

  • Return retakes -- Reflect on 1st Unit, now that you've been through a full unit cycle.
  • Check/Review Homeworks
    • Projectile trajectory answers
    • Pennington practice test

Homework: Finish any homework that you didn't complete for last class (including the projectile launcher practice problems -- p. 15; and Mr. Pennington's practice test -- p. 10-15)

 

Class 11 Friday, 9/24/21

Warm Up:  

None -- test retake day

Today:

  • Retake
  • Work time -- Project stuff or Mr. Pennington's old Chapter 3 Test (page 10-14 of the Unit 2 Packet Solutions 

Homework:

Class 10.5 Thursday, 9/23/21

Warm Up:  

Find a combination of initial angle and initial speed that will carry a projectile from the launch point to the target (assuming no air resistance).

You can guess, and I will check, with my private spreadsheet. :-)

Today:

  • Clarify the homework assignments.
  • Work time.  Complete your spreadsheet and then use Sheet 1 to complete the projectile practice problems on p. 15 of the packet.
  • Test retake tomorrow.  If you're not retaking the test, you can work on Mr. Pennington's old test (p. 10-14)

Homework:

  • Use Sheet 1 of your spreadsheet (or a copy of it) to complete the Projectile Launcher Spreadsheet Practice Problems on p. 15 of the Unit 2 Packet.
  • Sheets 1 and 2 of your group's trajectory spreadsheet are due by Monday.  At least one of you should submit the spreadsheet in Google Classroom.
Class 10 Wednesday, 9/22/21

Warm Up:  

1.  Based on the existing pattern, what should number should appear in the 7th row of column C?

2.  If we wanted to continue that pattern quickly and easily, how could we set up a spreadsheet to do it?

 

Today:

  • Please answer this brief multiple choice question (for our Wednesday afternoon teacher meeting).  Thanks!
  • Check/review homework
  • Trajectory Project:
    • Get Trajectory Contest Project Handout #1 PDF Version
    • Find a partner.
    • Modify this spreadsheet template to create the Sheet 1 ("Trajectory") of your Trajectory Project spreadsheet.
    • As you build your spreadsheet, use this screenshot to check your work.  Keep the yellow cells the same as mine so that you can use my calculations to verify yours. .  I plan to make a video during class and then make the video available on my YouTube channel.
    • FYI, here are what Sheets 2 and 3 will look like...
      • Sheet 2 (Launcher Calibration)
      • Sheet 3 (Launcher Calibration Graph)

Homework:

  • Divide tasks and work on the project at home.  Before class on Monday, you should be finished with Sheet 1, as well as the initial velocity calculators on Sheet 2.  Hopefully, you will calibrate your launcher on Monday (split block) and Tuesday. 
  • Test retake on Friday. 
Class 9.5 Tuesday, 9/21/21

Warm Up:   Sketch a head-to-tail diagram for each of the following.  We will look at the graphical solutions afterward.

1.  A baggage conveyor is moving in a direction 25 degrees South of East at a rate of 1.5m/s.  A bug riding on the conveyor has a velocity of 2m/s in a direction 30 degrees East of South.  What is the bug's heading and "speed on a still conveyor?"

2. A river's 3mph current flows in a direction 15 degrees West of North.  A swimmer, whose speed in still water is 2m/s, swims across the river with a heading 35 degrees South of West.  What is the swimmer's velocity, relative to the Earth?

3.  A superhero steward on an airplane is traveling in a direction 10 degrees East of South, and their speed is 580mph.  The plane's velocity is 460mph in a direction 5 degrees West of South.  What is the steward's heading and their "speed on a still plane?"

 

Sketches and answers: ---Argh!! #1 is wrong!  But 2 and 3 are right.

 

Today:

  • Update seating chart in A8
  • For even more non-orthogonal river problem practice, see the warm-ups from last year's classes #20 and #21.  A link to a video solution is included after each warm-up.
  • Tpmorrow:  Modify this spreadsheet template to create a mathematical model of a projectile's trajectory.  Make your own copy of the template.  Then use formulas to create the spreadsheet. .  I plan to make a video during class and then make the video available on my YouTube channel.
  • Check/review homework.

 

Homework:

  • Projectile Practice Problem #3 on p. 9 of the Unit 2 Packet Solutions
  • Don't forget that your chance to retake the test is on Friday.
Class 9 Monday, 9/19/21

Warm Up:  Suppose you shoot a projectile, horizontally, from the edge of a school tabletop that is 0.95m above the floor.  If the projectile hits the floor at a distance of 14 floor tiles from the table...

a.  What is the projectile's v0?

b.  How would you find the projectiles' final speed?

c.  How would you find the  angle at which the projectile hits the floor?

 

Today:

Rest of the week (tentative plan):

  • Tuesday -- create a trajectory spreadsheet
  • Wednesday -- begin trajectory contest project
  • Thursday -- continue project work
  • Friday -- test retake opportunity; Mr. Pennington's Unit 2 practice test

 

Homework:

Class 8.5 Friday, 9/17/21

Warm Up:  

1.  What do "air speed" and "speed in still water" mean?

2.  What is a "heading?"

3.  Let's practice resolving non-orthogonal vectors into their x and y components.

Identify the component and resultant vectors for the following "river problems."  Then sketch them using head-to-tail vector addition.

3.  A boat travels eastward at a rate of 3m/s.  The boat's heading is northeastward, and the boat's speed in still water is 8m/s.  What is the velocity of the water in which the paddler is paddling?

4.  A quadcopter has a velocity of 20m/s westward.  The wind is blowing southward at a rate of 10m/s.  What are the quadcopter's airspeed and heading?

5.  The driver of a golf cart on an aircraft carrier uses a compass to head northward.  The cart's speedometer reads 10mph.  The aircraft carrier's heading is eastward, and its speed in still water is15mph.  The ocean current is northwestward at a rate of 5mph.  What is the actual velocity (relative to the Earth) of the golf cart?

 

 

Today:

Homework:

  • River Problems 5-6.  These are non-orthogonal.  Solutions
Class 8 Thursday, 9/16/21

Warm Up:  

An airplane flying horizontally with a ground speed of 120 m/s releases care packages from a height of 4,800 meters.  If the packages are not affected by air resistance, how far ahead of the target (in the x dimension) should the packages be released?

 

Today:

Homework:

Class 7.5 Wednesday, 9/15/21

Warm Up:  

1.  Suppose the two vectors on the right represent two forces acting on the clam.  In what direction will the clam accelerate?  How will that acceleration compare to the accelerations we would observe if each force were acting alone?

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:

Homework:

  •  None
Class 7 Tuesday, 9/14/21

Warm Up:  None

Today:

  • Test

Homework:

  • None
Curling Technique — Curling — Jonathan HavercroftClass 6.5 Monday, 9/13/21

Warm Up:  How can we find the acceleration of an object as it slides across this floor, using only a stopwatch and the floor as measuring devices?

Today:

  • Check/review homework.
  • Interests of students in my two classes:
  • Questions about the test? -- Did anyone notice any more mistakes?
  • Here's a mostly nonsensical problem for the people who want to think about time travel...

If you could travel in time, and if you found yourself in the infinite loop of acceleration changes shown below... would you ever find yourself in the same location as another past self?  Explain by creating analagous graphs of velocity and distance vs time.

Homework:

  •  Study -- Hopefully you have been marking items in the notes and homework that were tricky the first time.  Go back and quiz yourself over those items.  They should no longer be tricky.  If they are, get help.  Memorize the formulas if you want an extra point. Kinematics formulas Quizlet
Class 6 Friday, 9/10/21

Warm Up:  

1.  Create a kinematics problems (on your own, or as a class).  Start by listing the available formulas and/or variable.

2.  If we graphed the motion of a vertically-launched projectile, which of these graphs would have at least one sharp corner in it? 

a. velocity vs. time    b. speed vs. time    c.  position vs. time    d. acceleration vs. time 

e. none of these    f. all of these

Today:

More Kinematics Practice (optional!)

  1. New questions and problems, based on form feedback...
    1. Extra Unit 1 Test Practice -- Questions and problems
    2. Extra Unit 1 Test Practice -- Answer Key The answer to #5 on the first section was wrong.  It should be correct now (if it's highlighted in yellow).  Solution to Extended Kinematics Problem
  2. Optional -- Here is some more practice creating graphs for events
    1. Blank PDF Handout -- "Extra Graphing Practice"
    2. Solutions(**On my graph of position vs time for the soccer ball kick, my graph should really have started and ended at the same position.)
    3. Video of me working through these and creating solutions
  3. Optional -- More practice with simple (one formula required) kinematics problems.  Make your own copy and expand column D to see the answers.

Homework:

  •  "Classic River Problem" on page 4 of the Unit 2 Packet.
Class 5.5 Thursday, 9/9/21

Warm Up:

Sketch a graph of acceleration vs. time for a suction cup Nerf dart that is shot at a wall.  Start your graph just before the dart begins to move, and end it just after the dart stops.

Today:

  • Check/review homework.  Improving our troubleshooting efficiency.
  • Pinpoint weaknesses.
  • Test on Tuesday:  42 points total
    • 16 multiple choice / short answer -- 1 point each
    • 1 unit conversion -- 2 points
    • 4 Problems -- 4 points each
    • Extended Problem -- 5 parts, worth 2 points each
    • Bonus (optional) -- 1 point if correct
    • 1 point for opting out of the formula sheet.
  • Fill out this form if you want to request extra practice.

Homework:

Class 5 Wednesday, 9/8/21

Warm Up:

Mr. Chase pointed out that there are 9 types of motion.  This is based on the fact that Velocity can be +, -, or 0, and acceleration can also be +, -, or 0.  A pendulum swinging back and forth demonstrates 8 out of these 9 types of motion.

1.  Graph the pendulum's X velocity over one full period (over and back) of motion.

2.  Identify where in the video each of those 8 types of motion occurs.

3.  Which of these 9 types of motion is not demonstrated?

 

Today:

Homework:

Class 4.5 Tuesday, 9/7/21

Warm Up:  Simplify this "extended" kinematics problem by drawing a diagram and identifying intervals with unique accelerations and or unique initial/final conditions.  You don't have to solve the problem.

A ball is dropped (in free-fall) from a height of 16m. When it reaches a speed of 3m/s, the ball contacts a compression spring.  The ball continues downward, slowing down as it compresses the spring and then speeding up as it is thrown back upward by the spring.  For purposes of calculation, you can consider the ball to experience a constant +35m/s2 acceleration during its 0.15 seconds of contact with the spring. 

1.  What is the height of the ball when the spring is fully compressed?

2.  What is the maximum height of the ball after it leaves the spring?

Today:

Homework:

Class 4 Friday, 9/3/21

Warm Up:   

1. Suppose students enter our school at a rate of 54 pounds/sec (pounds of student).  After they enter, they lie down,  head-to-toe, forming a line whose length is the sum of their heights.  Since an average 16 year old student's weight:height ratio is about 2.07 lb/in (and assuming these are all average students with that ratio), how many days will it take them to form a line 3 miles long?

2.  Is this actually a "possible problem," in the sense that it could happen and that it is solvable given the information above?

Today:

  • Warm-up -- discuss how dimensional analysis works.
  • Check/review homework
  • Spool tractor challenge -- accuracy and speed

Homework:

Class 3.5 Thursday, 9/2/21

Warm Up:

Consider the case of this ball.  At t = 0s, the ball is free-falling directly upward at a height o 10m, with a speed of 20m/s.  Sketch graphs of the ball's position, velocity, and acceleration (vs. time) over the next 4 seconds. [For simplicity, use g =10m/s2 instead of g = 9.8m/s2]

Today:

  • Check/review homework
  • Spool tractor practice

Homework:

  •  Complete the problems section of Mr. Pennington's Old 1-D Kinematics Test (Packet page 20). **Note that problem 1 is a unit conversion problem, which we haven't been over in class (though you should be well-versed in unit conversions from Chemistry).  You will have a chance to practice unit conversions if you want more practice.  And in problem #2 you'll need to know that circumference = pi*d.  Here's the Answer Key. If you have questions, watch this Video for Help with the Problems
Class 3 Wednesday, 9/1/21

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:

Homework:

  •  Complete the rest of the multiple choice on Mr. Pennington's Old 1-D Kinematics Test (Packet pages 18-20).  Answer Key. If you have questions, watch this Video for Help
Class 2.5 Tuesday, 8/31/21

Warm Up:  What is a spool tractor?  How does one work?

Today:

 

Homework:

  • Complete Multiple Choice 1-12 from Mr. Pennington's Old 1-D Kinematics Test (Packet pages 17-18).  Answer Key. If you have questions, watch this Video for Help
Class 2 Monday, 8/30/21

Warm Up:

1.  Assuming that the man in the picture is 2m tall, and the frame rate of the camera was the usual 30 frames per second, what was the approximate maximum speed of the object?

2.  Based on your answers, do you think the assumption of 30 frames per second was too low, too high, or about right?

Today:

Homework:

Class 1.5 Friday, 8/27/21

Warm Up:

Use the velocity vs time graph on the right to sketch the shape of a corresponding position vs time graph.  [Assume that motion away from the sensor is positive, and motion toward the sensor is negative.]

Today:

Optional Reading -- Online Textbook:

Homework:

Class 1: Thursday, 8/26/21

Warm Up:  Suppose you're involved in a 2 lap race.  If you want your overall average speed to be twice as fast as your speed for the first lap, how much faster do you have to go during the 2nd lap? [To calculate average speed you can use rate = distance / time]

Today:

Optional Online Textbook Reading:

Homework:

Class 0.5: Wednesday, 8/25/21

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:

Links:

Online Textbook Reading:

Homework: None