Class
63 Tuesday, 3/26/19 WarmUp : 1. Why doesn't a bird on an uninsulated power line get shocked? 2. Would a bird get shocked if it landed on a Van de Graaff generator? 3. How can we test #2? 4. Why shouldn't you try #1? Today:
Online Textbook Reading: Chapter 18.4 and 18.5 Homework: Study 

Class
63 Monday, 3/25/19 WarmUp : 1. What is a spark? 2. How does a plasma ball work? Breakdown voltages, relative to air. tesla coil 3. How does a jacob's ladder work? Today:
Online Textbook Reading: Chapter 18.4 and 18.5 Homework: Finish 18.718.8 practice 18.7 Solutions 18.8 solutions Video solutions: 18.7, number 2 18.718.8  the rest 

Class
62.5 Thursday, 3/21/19 WarmUp : 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? 3. Diagram C shows two conductors with excess positive charges. Why do the excess charges reside on the conductors' surfaces? Why are the charges closer together near the pointy part of the rightmost conductor? What implications does this have for Van de Graaff generator design? Today:
Online Textbook Reading: Chapter 18.7 and 18.8 Homework: Electrostatics Practice Test (Mr Pennington's Old Test)  Answer Key 

Class
62 Wednesday, 3/20/19 WarmUp : How does a Van de Graaff Generator Work? MIT video  inducing dipoles with a VDG Today:
Online Textbook Reading: Chapter 18.4 and 18.5 Homework: 

Class
61.5 Tuesday, 3/19/19 WarmUp : 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 negative charge... 1. What is the charge of the plate after it is touched by the scientist? 2. Explain how the conducting plate becomes charged. 3. What is the ground in this demonstration? Today:
Ch 18.3: Coulomb's Law 18.3 Notes and Practice Filledin Notes Online Textbook Reading: Chapter 18.3 Homework: Complete 15 in 18.3 Notes and Practice Solutions 

Class
61 Monday, 3/18/19 WarmUp : 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? 5. What events contributed to this gas station fire? Today:
The rest of the quarter:
Online Textbook Reading: Chapter 18.1 and 18.2 Homework: 

Class
60.5 Friday, 3/15/19 WarmUp : See example slide, on the right.
Today:
Online Textbook Reading: Homework: 

Class
60 Thursday, 3/14/19 WarmUp : 1. What are some ways of tuning a string instrument? 3. How do you know what key a song is in, based on chords? How can you change the key? Today: Last full work day. Tomorrow we clean up and store the instruments in a careful, intentional manner. Any additional work will need to be done during flex.
Online Textbook Reading: Homework: 

Class
59.5 Wednesday, 3/13/19 WarmUp : How do this bridge and nut need to be modified? Today:
Online Textbook Reading: Homework: 

Class 59 Tuesday, 3/12/19 WarmUp : Watch videos  saddles, knobs, plastic tuners (easy green ones, black ones) Today:
Online Textbook Reading: Homework: 

Class
58.5 Monday, 3/11/19 WarmUp : Today:
Online Textbook Reading: Homework: 

Class
58
Thursday, 3/9/19 WarmUp : These pictures compare the fret "wire" that we will be using to standard fret wire. We will wrap the fret wire. Why does the fret wire need to be wrapped very tightly? Today:
Online Textbook Reading: Homework: 

Class
57.5
Thursday, 3/7/19 WarmUp : 1. How do you load new sandpaper into this type of finishing sander? 2. What's the number 1 rule for prolonging the life of sandpaper in the finishing sander? Today:
Online Textbook Reading: Homework: 

Class
57
Wednesday, 3/6/19 WarmUp : What hazards are posed by a belt sander? Today:
Online Textbook Reading: Homework: 

Class
56.5
Tuesday, 3/5/19 WarmUp : What are the most important things to remember when you're using a scroll saw? Today:
Online Textbook Reading: Homework: Email this to Mr. Stapleton... Modify this fret calculation template to create a spreadsheet that will calculate fret positions for any length string. You will use this spreadsheet for calculating your instrument's fret positions. Answers for a 33cm bridgetonut distance @440Hz. Video showing how to do this. 

Class
56
Monday, 3/4/19 WarmUp : The frequency of a wave describes number crests or troughs that pass a particular point in a given amount of time (a.k.a. cycles per second). The units are Hertz (Hz). 1. What is the frequency of the wave pattern on the right? 2. If the distance between two successive crests (i.e. wavelength) is 4m, what is the speed of the waves on the right? 3. What is the formula for wave speed, in terms of frequency and wavelength? Today:
Online Textbook Reading: Homework: None 

Class
55.5
Friday, 2/22/19 WarmUp : 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 the wood into smaller pieces? Can you describe the proper technique? One solution. Today:
Online Textbook Reading: Homework: None 

Class
55
Thursday,
2/21/19 WarmUp : No warmup Today:
Online Textbook Reading: Homework: None 

Class
54.5 Wednesday,
2/20/19 WarmUp : A quadcopter has four propellers that usually alternate in their directions of rotation.
Today:
Online Textbook Reading: Chapter 10 Homework: Test tomorrow


Class
54 Tuesday,
2/19/19 WarmUp :
Today:
Online Textbook Reading: Chapter 10 Homework:


Class
53.5 Monday,
2/18/19 WarmUp : In the picture on the right, the wheel is spinning, and the guy is sitting motionless 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: Multiple choice from Rotational Motion Test Review #1 Solutions to Pennington Test Review


Class
53 Friday,
2/15/19 WarmUp : Explain how this jar lid closure works, in terms of Net Torque  especially T_{net}=Frsinθ. You might also consider F=kx. Today:
Online Textbook Reading: Homework:


Class
52.5 Thursday,
2/14/19 WarmUp : No warmup todayToday:
Online Textbook Reading: Homework:


Class 51.5 Tuesday, 2/12/19 WarmUp : 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. Suppose the bottom end of the ramp is frictionless, and when they reach the bottom, the objects hit a vertical, frictionless wall. What motions, if any, would continue after impact? 3. How this event be different if the objects varied in mass and/or height? 4. The round objects are affected by friction. Would the result be different in a totally frictionless situation? Explain. Today:
Online Textbook Reading: Homework:


Class
51 Monday,
2/11/19 WarmUp : 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 Reading: Homework:


Class
50.5 Friday,
2/7/19 WarmUp : 1. What does a differential do? 2. How does a differential work? Today:
Online Textbook Reading: Chapter 8: Linear Momentum and Collisions Homework:


Class
50 Thursday,
2/7/19 WarmUp : What do you notice about this comic situation portrayed in the Stall Street Journal? Today:
Online Textbook Reading: Chapter 8: Linear Momentum and Collisions Homework: 

Class
49.5 Wednesday,
2/6/19 WarmUp : Suppose you need to screw an abutment into a fixture that is implanted in someone's jaw. How can you make sure that you screw it in just tight enough, but not too tight? Today:
Online Textbook Reading: Chapter 8: Linear Momentum and Collisions Homework:


Class
49 Tuesday,
2/5/19 WarmUp : In the rotational (angular) motion unit, we will be using new units that are analogous to our current, linear units. You will need to be able to work in radians. 1. 360º = _____ radians 2. 90º = _____ radians Today:
Online Textbook Reading: Chapter 8: Linear Momentum and Collisions Homework: Torque Practice (Pennington) Torque Practice Solutions 

Class
48.5 Monday,
2/3/19 WarmUp : Shoot a board with Nerf darts and see if our answers to Friday's warmup were correct. Today:
Online Textbook Reading: Chapter 8: Linear Momentum and Collisions Homework: Linear Momentum Practice Quiz (last year's quiz, mostly) Solutions 

Class
48 Friday,
2/1/19 WarmUp : Suppose I stand a board on end and shoot it with a Nerf^{ ® }dart. 1. 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? 2. Which experiences a greater impulse, the dart or the board? Or do they experience the same impulse? Today:
Online Textbook Reading: Chapter 8: Linear Momentum and Collisions Homework: Complete # 8,9,10,11,13,14 in Coefficient of Restitution, Plus Various Momentum Problems Solutions (except 1314) Solutions to 13 and 14 

Class
47.5 Thursday,
1/31/19 WarmUp : No warmup today. Mr. Stapleton gone. Today:
Online Textbook Reading: Chapter 8: Linear Momentum and Collisions Homework:


Class
47 Wednesday,
1/30/19 WarmUp : How can an understanding of momentum help you turn a towel into a better whip? Today:
Online Textbook Reading: Chapter 8: Linear Momentum and Collisions Homework:


Class
46.5 Tuesday,
1/29/19 WarmUp : No warmup today. Not enough time.Today:
Online Textbook Reading: Chapter 8: Linear Momentum and Collisions Homework:


Class
46 Monday,
1/28/19 WarmUp : 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:


Class
45.5 Friday,
1/24/19 WarmUp : When you're ready to drop your egg, tell me your board heights, and I will position the board for you. Today:
Homework: None 

Class
45 Thursday,
1/24/19 WarmUp : 1. How can you attach weights to the egg bungee jump harness in the picture? 2. How do you attach the bungee to the egg harness? Today:
Homework: Complete problem #2 in Bungee Jumper Problems solution to part 1 

Class
44.5 Wednesday,
1/23/19 WarmUp : An egg with a mass of 0.1kg is dropped from a height of 3m. When the egg reaches a height of 2.5m, it begins stretching a spring with k = 1.5N/m. At what height will it stop stretching the spring? Answer Today:
Homework: Create a graph to find the stopping point of the bungee jumper. Complete this template. Write down your final answer on paper.


Class
43.5 Monday,
1/14/19 WarmUp : More YoYo 1. The graphs on the right correspond to one downup cycle of a yoyo. How can the yoyo speed graph be correct if the velocity graph is wrong? 2. When the yoyo stalls at the lowest point in its path, what kind of PE and KE does it have? 3. Given that a yoyo is not a 100% efficient device, how does the operator make it come all of the way back to the top? How does this work, in terms of KE and PE? 4. Is there a way to get the yoyo to return to the hand without adding any extra KE to the yoyo? Today:
Homework:


Class
43
Friday,
1/11/19 WarmUp : None  start quiz immediately Today:
Online Textbook (OpenStax) Reading: Homework:


Class
42
Thursday,
1/10/19 WarmUp : 1. How does this yoyo work? What do the springs and steel balls do? 2. Suppose a 100% efficient yoyo falls down and comes up through one cycle. Would either (or do both) of these graphs realistically portray its motion? Explain. 3. What would graphs of KE and PE look like?
Today:
Online Textbook (OpenStax) Reading: Homework:


Class
41
Tuesday,
1/8/19 WarmUp : 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:
Online Textbook (OpenStax) Reading: Homework:


Class
40.5
Monday,
1/7/19 WarmUp : Both graphs represent work that was done over a 3m distance. Estimate the work done in each case. Today:
Online Textbook (OpenStax) Reading: Homework:


Class
40
Friday,
1/4/19 WarmUp : 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?
Today:
Online Textbook (OpenStax) Reading: Homework: 

Class
39.5
Thursday,
1/3/19 WarmUp : If we tighten a rope between the end of the board and the digital scale, the digital scale will tell us the tension in the rope. How tight do you think we can get the rope? What's the best way to tighten a rope if you want to be able to untie it later? Today:
Online Textbook (OpenStax) Reading: Homework:


Class
39
Wednesday,
1/2/19 WarmUp : For an ideal spring, the applied force is directly proportional to the stretch distance*. The spring constant, k, is the ratio of force to stretch distance. The units we will use for k are 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. If we use x for a spring's stretch displacement, derive a formula for the force exerted by the spring. F_{spring} = ? 3. How much work is required to stretch the spring from a stretch distance of 0m to a stretch distance of 1m? 4. How much work is required to stretch a spring from 0 to x meters if its spring constant is k? In other words, derive the formula for PE_{spring.} _{*In the case of a compression spring, x is the compression distance.} Today:
Online Textbook (OpenStax) Reading: Homework:


Class
38.5
Friday,
12/21/18 WarmUp : In order to deliver his presents on time, what forces, accelerations, and other physical obstacles does Santa encounter? Today:
Online Textbook (OpenStax) Reading: Homework:


Class
38
Thursday,
12/20/18 WarmUp : A trebuchet's projectile is launched as its counterweight falls, thereby turning PE into KE and accelerating the projectile. 1. Does the projectile do work on the counterweight or viceversa? Or does each do work on the other? Explain. 2. At which end of the trebuchet arm does the work being done look like this ⇒ Fd ? 3. Record the current temperature, air pressure, and relative humidity. Today:
Online Textbook (OpenStax) Reading: Homework:


Class
37.5
Wednesday,
12/19/18 WarmUp : 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. Identify the task (work) in each picture. 2. For each picture, identify the machine (s). 3. For each machine, tell how the machine alters the distance over which force must be applied by the human using the machine. 4. How does the machine alter the force that the human must apply? 5. Which machine is fundamentally different from the other 3? Why? Today:
Online Textbook (OpenStax) Reading: Homework:


Class
37 Tuesday,
12/18/18 Warm Up: 1. What does the "sisyphus train" do? 2. How did it get that nickname? 3. In the context of physics energy problems, some forces are called conservative, and others are referred to as nonconservative. Can you guess the difference between the two?
Today:
Online Textbook (OpenStax) Reading: Homework:


Class
36.5 Monday,
12/17/18 Warm Up: 1. What is the difference between kinetic energy and potential energy? 2. 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) 3. How much potential energy (PE) will it have when it reaches its highest point? 4. As the ball rises, what is doing work on what? 5. What is the formula for gravitational PE, and where does it come from? Today:
Online Textbook (OpenStax) Reading: Homework: Complete Problem #5 in Energy and Work. Answers/solutions 

Class
36 Friday,
12/14/18 Warm Up: None Today:
Online Textbook (OpenStax) Reading: Homework: None 

Class
35.5 Thursday,
12/13/18 Warm Up: 1. What is the purpose of a centrifuge? 2. Can you use a bathroom scale to find the weight of the Earth? Today:
Online Textbook (OpenStax) Reading: Homework:


Class
35 Wednesday,
12/12/18 Warm Up: 1. How are gforces dangerous to pilots? 2. In this video, a driver attempts to traverse a large looptheloop. In order to safely complete his mission, how many g's do you suppose the driver needs to tolerate? Today:
Online Textbook (OpenStax) Reading: Homework:


Class
34.5 Tuesday,
12/11/18 Warm Up: 1. Approximately how fast is the jogger in this video moving, relative to the center of rotation? 2. If the jogger turned around and jogged the other way, would he feel any different? 3. Is there a centrifugal force in this video? Today:
Online Textbook (OpenStax) Reading: Homework:


Class
34 Monday,
12/10/18 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? How do you know? 2.
3. What is a geosynchronous satellite? 4. What's the difference between a geosynchronous orbit and a geostationary orbit? 5. What is a space elevator? Today:
Online Textbook (OpenStax) Reading: Homework:


Class
33.5 Friday,
12/7/18 Warm Up: From 20162017 EPS 200... The Sun, Earth, and Moon are continually spaghettifying one another. On Earth, we see the effects of this spaghettification in the form of tides. 1. What causes spaghettification? 2. How much gravitational force do the Sun and Moon each exert on 1,000,000 pounds of water? 3. Even if there were no water on Earth, there would still be tides, just as there are tides on the Moon. Describe these tides. 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 Today:
Online Textbook (OpenStax) Reading: Homework:


Class
33 Thursday,
12/6/18 Warm Up: 1. At what approximate date is the Earth orbiting with the fastest speed? When is it orbiting the slowest? 2. Rank the seasons in order of length. Answer 3. How are our solstice and equinox dates determined? Today:
Online Textbook (OpenStax) Reading: Homework:


Class
32.5 Wednesday,
12/5/18 Warm Up: Are astronauts weightless when they are in the international space station? Is this candle weightless? Today:
Online Textbook (OpenStax) Reading: Homework: Finish the elliptical orbits activity. Elliptical Orbits Activity 

Class
32 Tuesday,
12/4/18 Warm Up: Hank is carrying a very wide tray of sand that won't fit through a doorway. How can Hank get the tray through the doorway without spilling the sand? Today:
Online Textbook (OpenStax) Reading: Homework: The following can be found in Notes: Circles, Gravity, Kepler Solutions solution to #10 with 3rpm


Class
31.5 Monday,
12/3/18 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:


Class
31 Friday,
11/29/18 Warm Up: If you made a hole straight through the Earth, where would the hole come out on the other side? Today:
Online Textbook (OpenStax) Reading: Homework:


Class 30.5
Thursday,
11/29/18 Warm Up: According to physics lore, if you made a hole through the center of the Earth, and jumped in, you would readch the other side in approximately 42 minutes (assuming no friction). 1. How could this be calculated using Newton's Law of Gravitation? 2. It turns out that the trip would not actually take 42 minutes. Why? Would the trip actually be longer or shorter? 3. What if there were air resistance? 4. Where would you come out? Excel spreadsheet  falling through the earth
Today:
Online Textbook (OpenStax) Reading: Homework:


Class 30 Wednesday,
11/28/18 Warm Up: A Google search result says the acceleration of gravity on Earth is 9.807m/s^{2}. For multiple reasons,that is almost always not the precise acceleration of a falling object. 1. What are those reasons? 2. When would this be the exact acceleration of a falling object? Today:
Online Textbook (OpenStax) Reading: Homework:


Class
29.5 Tuesday,
11/27/18 Warm Up: A waiter is carrying a chunk of bone, basted in synovial fluid, on a flat, bone tray that is coated with synovial fluid. The tray is angled at 45º, as shown. Why doesn't the bone chunk slip off of the tray? Today:
Online Textbook (OpenStax) Reading:
Homework:


Class
29 Monday,
11/26/18 Warm Up: A 1kg mass is suspended by a string from the ceiling of a train car. The front and rear of the car are open, so the mass is exposed to the oncoming wind. The velocity of the train and the angle in the diagram both remain constant. [Air density = 1.2kg/m^{3}. C_{d sphere} = 0.45. A_{sphere} = 0.05m^{2}] 1. How would we draw the forces acting on the sphere? 2. Given g = 10m/s^{2}, what is the tension in the string? 3. What is the velocity of the train? Today:
Online Textbook (OpenStax) Reading:
Homework:


Class
28 Thursday,
11/15/18 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:
Assignment Due Dates:


Class
27.5 Wednesday,
11/14/18 Warm Up: 1. How does Clifford Heath's water rocket simulator work? What can we learn from it? 2. How could you modify your spreadsheet to calculate: 1) "crashdown speed?" 2) Δx? Today:
Assignment Due Dates: These assignments are not optional. If you do not complete them, they will count as zeroes.


Class
27 Tuesday,
11/13/18
Warm Up: Two
boxes are initially at rest, relative to a the elevator in which they
sit.
When
a
person exerts a 200N rightward force over a time interval of 1 second,
the 20kg box moves a distance of 1.38m rightward.
What is the
10kg block's
x displacement
during that same time interval? Today:
Assignment Due Dates: These assignments are not optional. If you do not complete them, they will count as zeroes.


Class
26.5 Monday,
11/12/18 Warm Up: Suppose someone straps a stuffed koala to a rocket and then launches the koala and rocket directly upward. The rocket thrust lasts for 1 second and provides a constant force of 1,000N. During thrust, the average mass of the koala + engine + fuel + harness = 10kg. Ignoring air resistance, calculate the maximum height reached by the koala? For ease, you can assume that g=10m/s^{2}. Today:
Tomorrow: Work time to finish whatever you need to finish. Assignment Due Dates: These assignments are not optional. If you do not complete them, they will count as zeroes.


Class
26 Friday,
11/9/18 Warm Up: 1. What purpose does the formula in column Q serve? 2. Why don't the first several rows in column Q have formulas? Today:
Homework: 

Class
25.5 Thursday,
11/8/18 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. 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:
Homework: 

Class
24.5 Tuesday,
11/6/18 Warm Up: Find the acceleration of each block and the tensions in the two strings. To make your work easier, use g=10m/s^{2} Assume that the pulleys and strings are massless and frictionless. Today:
Homework:


Class
24 Monday,
11/5/18 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 an elevator, and the elevator suddenly began to accelerate downward at 1g? 4. What is the source of the "butterflies in the stomach" when we fall? Today:
Homework:


Class
23.5 Friday,
11/2/18 Warm Up: The figure on the right shows Atwood's Machine. Write an equation for the acceleration of the masses in terms of m_{1}, m_{2}, and g. You may assume that the rope is massless and that there is no friction. Today:
Homework:


Class
23 Thursday,
11/1/18 Warm Up: If you need to stop a car quickly, why should you avoid locking the tires or skidding? Today:
Homework:


Class
22.5 Wednesday,
10/31/18 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 large nail through the 2"x4"? Is this a good idea? Today:
Homework:


Class
22 Tuesday,
10/30/18 Warm Up: How many 100 psi water bottles would it take to launch a human? Today:
Homework:


Class
21.5 Monday,
10/29/18 Warm Up: 1. If a Wiffle® Ball has a mass of about 45g, what is the upper limit of the amount of force a thrower can apply to a Wiffle Ball during the throw? 2. Why is there a limit to how much force can be applied to a thrown Wiffle Ball? Today:
Online Textbook (OpenStax) Reading:
Homework:


Class
21 Friday,
10/26/18 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 "freefalling" cat? 3. When does a falling cat experience maximum net force? Today:
Online Textbook (OpenStax) Reading:
Homework:


Class
20.5 Thursday,
10/25/18 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:
Online Textbook (OpenStax) Reading:
Homework:


Class 20
Wednesday,
10/24/18 Warm Up: 1. In a game of tugofwar, who pulls the hardest  the winners, the losers, or neither? Explain. 2. Why is the word pull in italics? Today:
Online Textbook (OpenStax) Reading:
Homework:


Class 19.5
Tuesday,
10/23/18 Warm Up: None Today:
Online Textbook (OpenStax) Reading:
Homework: Due on Wednesday:


Class 19
Monday,
10/22/18 Warm Up: None Today: 1) Watch this video. Make sure that you adjust the three volume controls: 1) computer volume, 2) YouTube volume, 3) Stereo Receiver volume
2) Work on Rockets:
3) Work on the homework (below) Online Textbook (OpenStax) Reading:
Homework: Due on Wednesday:


Class 18.5
Wednesday,
10/17/18 Warm Up: 1. How does a water rocket work? 2. Would a water rocket work better or worse in outer space? Explain. Today:
Online Textbook (OpenStax) Reading:
Homework:


Class 18
Tuesday,
10/16/18 Warm Up: Take a look at the 2D kinematics data relating to homework completion and test scores. What do you think? Means: 68% (A5/6), 84% (A7/8) Medians: 63% (A5/6), 88% (A7/8) Today:
Online Textbook (OpenStax) Reading:
Homework:


Class 17.5
Monday,
10/15/18 Warm Up: There is a heavy object suspended from the ceiling by 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:
Online Textbook (OpenStax) Reading:
Homework:


Class 17
Friday,
10/12/18 Warm Up: Test Today. No Warmup. Today: Chapter 3 Test Online Textbook (OpenStax) Reading:
Homework:


Class 16
Thursday,
10/11/18 Warm Up: 1. 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? 2. 1m/s = ____ mph. For tomorrow's test, memorize this or be able to calculate it based on a known conversion. Today:
Online Textbook (OpenStax) Reading:
Homework:


Class 15.5
Tuesday,
10/10/18 Warm Up: No Warmup Today:
Online Textbook (OpenStax) Reading: Homework:


Class 15
Tuesday,
10/8/18 Warm Up: No Warmup Today:
Online Textbook (OpenStax) Reading: Homework:


Class 14.5
Monday,
10/8/18 Warm Up: Will the blue hunter hit the monkey? Today:
Online Textbook (OpenStax) Reading: Homework:


Class 14
Friday,
10/5/18 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 fake monkey slips and freefalls from the treetop. [You may assume that this takes place in a vacuum on a flat earth.] 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 had stayed in position at the top of the tree? 3. Does the answer to either of these questions depend on the bullet velocities? Today:
Online Textbook (OpenStax) Reading: Homework: 

Class 13.5
Thursday,
10/4/18 Warm Up: Can you think of a more precise method of calibrating your launcher?  rather than shooting horizontally from a stool? What does precision mean? Today:
Online Textbook (OpenStax) Reading: Homework:


Class 13
Wednesday,
10/3/18 Warm Up: At the angle shown, can the projectile launcher hit the target? If not, how should the launcher be adjusted? Today:
Online Textbook (OpenStax) Reading: Homework: 

Class 12.5
Tuesday,
10/2/18 Warm Up: 1. The pilot of a small plane is navigating by pointing her plane directly southward while maintaining an air speed of 100m/s. If the plane has an actual eastward velocity of 50m/s, what is the velocity of the air that surrounds the plane? To eliminate some calculations, you can describe the wind velocity by providing its two component vectors. 2. If there were no windshield, and the propeller were momentarily removed, would the pilot feel air blowing from straight ahead or from some other direction? Today:
Online Textbook (OpenStax) Reading: Homework:


Class 12
Monday,
10/1/18 Warm Up: Sketch the component and resultant vectors for the following "river problems." 1. A paddler travels eastward at a rate of 3m/s. The paddler's heading is northeastward, and the paddler's speed in still water is 8m/s. What is the velocity of the water in which the paddler is paddling? 2. 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? 3. The driver of a golf cart on an aircraft carrier uses a compast to head northward. The cart's speedometer reads 10mph. The aircraft carrier's heading is eastward, and it's 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:
Online Textbook (OpenStax) Reading: Homework:


Class 11.5
Friday,
9/28/18 Warm Up: 1. How do you enter a formula in a spreadsheet (e.g. Google Sheets, or Excel)? 2. If you don't know how to do something in a spreadsheet, how can you find out how it's done? 3. How would you create a spreadsheet like the one on the right? Given a projectile's initial speed and launch angle, this spreadsheet calculates the x and y positions of the projectile at any given time. Today:
Coming up:
Online Textbook (OpenStax) Reading: Homework/Deadlines:


Class 11
Thursday,
9/27/18 Warm Up : Two canoe paddlers begin at the starting point in the diagram on the right. They paddle with a constant water speed. Paddler A maintains a westward heading while paddler B keeps the canoe pointed at the small island. 1. What is the difference between water speed and speed? 2. Which paddler is following a heading? 3. Describe the shape of the path followed by each paddler. 4. Now suppose we increase the scale of the problem, remove any current, and provide paddler A with a compass only at the beginning of her journey. She points her canoe westward, begins traveling in that direction, and maintains her speed in a perfectly straight path. Assuming that her path is perfectly straight, will she reach the island 1,000 miles away? Explain. 5. What does the previous question suggest about the assumptions of river problems in this class? 6. In this class, river problems will involve three velocities, a) the velocity of a medium (e.g. river water, or moving air) relative to the Earth, b) the speed of an object relative to the medium, and its direction (heading), relative to the Earth, and c) the velocity of the object relative to the Earth. Which of these three velocities will be the resultant vector in river problems? [It may be easier to think of these as the current's direction, the object's heading, and the object's actual path.] Today:
Coming up:
Online Textbook (OpenStax) Reading: Homework:


Classes 9.5 (Monday, 9/24), 10 (Tuesday, 9/25),
and 10.5 (Wednesday, 9/27) Work through these notes and problem sets. Please help one another. Also ask Mr. Chase for help. If you sign up for my Flex, he is in the same room (C211/212). Online Textbook (OpenStax) Reading:


Class
9 Friday,
9/21/18 Warm Up : 1. What are sine, cosine, and tangent? 2. Find the missing vector magnitudes on the right. Today:
Online Textbook (OpenStax) Reading: Homework:


Class
8.5 Thursday,
9/20/18 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:
Online Textbook (OpenStax) Reading: Homework: 

Class
8 Wednesday,
9/19/18 Warm Up: No warmup today Today:
Online Textbook (OpenStax) Reading: Homework: 

Class
7.5 Tuesday,
9/18/18 Warm Up: 1. Propose an explanation for why this velocity graph is so scattered looking. 2. What five variables should you look for in kinematics problems? Today:
Homework:


Class
7 Monday,
9/17/18 Warm Up: 1. Eliud Kipchoge ran 26.22 miles in a time of 2:01:39. What was his average Δt, in minutes and seconds, for each mile? 2. Why is a marathon 26 miles, 385 yards? 3. Take a look at the formulas that you will be given on the test. Today:
Online Textbook (OpenStax) Reading: Homework:


Class
6.5 Friday,
9/14/18 Warm Up: Sometimes people celebrate special occasions by firing guns into the air. 1. Is this a dangerous way to celebrate? Why, or why not? 2. Why don't clouds fall out of the sky? Calculated terminal velocities of various spheres. Today:
Online Textbook (OpenStax) Reading: Homework: 

Class
6 Thursday,
9/13/18 Warm Up: 1. 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. 2. All of the speed calculations in the screenshot on the right (blue) are slightly off, and the last speed calculation (red) is really, really off. Why?
Today:
Coming Up:
Online Textbook (OpenStax) Reading: Homework: 

Class
5.5 Wednesday,
9/12/18 Warm Up: Match each position vs. time graph with the correct velocity and acceleration graph. Today:
Coming Up:
Online Textbook (OpenStax) Reading: Homework:


Class
5 Tuesday,
9/11/18 Warm Up: A ball is launched directly upward from the Earth's surface. The ball returns to Earth and hits the ground after a time of 10 seconds. Assuming no air resistance and g≈10m/s^{2}, fill in the values in the diagram on the right. [Though the diagram appears to show horizontal motion, assume that there is none.] Today:
Online Textbook (OpenStax) Reading: Homework:


Class
4.5 Monday,
9/10/18 Warm Up: The symbol "g" usually represents the absolute value of the acceleration of gravity near Earth's surface (in the absence of air resistance). The approximate value of g is 9.8m/s^{2}. For the sake of simplicity, use g = 10m/s^{2} to complete the motion graphs for an object with v_{0} = 20m/s and y_{0} = 0m. [Ignore air resistance.] Today:
Tomorrow:
Online Textbook (OpenStax) Reading: Homework:


Class
4 Friday,
9/7/18 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:
Online Textbook (OpenStax) Reading: Homework:


Class
3.5 Thursday,
9/6/18 Warm Up: 1. How does the Amazing Water and Sound Experiment work? 2. Answer to yesterday's warmup#3?. Today:
Online Textbook (OpenStax) Reading: Homework: 

Class
3 Wednesday,
9/5/18 Warm Up: 1. Assuming that the man in the picture is 2m tall, and the frame rate of the camera was 30 frames per second, what were the approximate maximum and minimum speeds of the object? 2. Based on your answers, do you think the assumption of 30 frames per second was too loww, too high, or about right? 3. If you could travel in time, and you found yourself in the infinite loop of acceleration changes shown below... a) what might your velocity and position graphs look like?, and b) would you ever find yourself in the same location as another past self? If so, show how this could occur.
Today:
Online Textbook (OpenStax) Reading: Homework:


Class
2.5 Tuesday,
9/4/18 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:
Handouts: Online Textbook (OpenStax) Reading: Homework: 

Class
2 Friday,
8/31/18 Warm Up: Use the velocity vs time graph on the right to sketch the shape of a corresponding position vs time graph. [Hint: positive velocity corresponds to movement away from a motion sensor.] Today:
Handouts: Online Textbook (OpenStax) Reading: Homework:


Class
1.5 Thursday,
8/30/18 Warm Up: For each letter, describe what is happening to the person's speed and direction during the 10 seconds represented on the graph. Today:
Handouts: Online Textbook (OpenStax) Reading: Homework:


Class
1: Wednesday,
8/29/18 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? Today:
Handouts: Online Textbook (OpenStax) Reading: Homework:
