Class 39:
Friday
1/22/2021 Warm Up: None Gold:
Blue: Prepare for your optional test retake on Monday and friction fire on Tuesday. 
Class 38:
Thursday
1/21/2021 Warm Up: None Gold:
Blue: Prepare for your optional test retake on Monday and friction fire on Tuesday. 
Class 37:
Wednesday
1/20/2021 Warm Up: None Today I will just be going over the tests. To help you prepare for the retake, I will provide a video link to the solutions.If you have questions about the optional (extra credit) project, I can answer those. 
Class
36:
Tuesday
1/19/2021 Warm Up: None  Blue and Remote Test Today Pick up a bearing block and/or twine if you want them 
Class
35:
Friday
1/15/2021 Warm Up: None  Gold Test Today Pick up a bearing block and twine if you want them

Class
34:
Thursday
1/14/2021 Warm Up: Draw a force diagram for each of the five numbered moments in the following scenario. Use arrows to represent the individual and net force vectors, and name all of the forces appropriately. Arrow lengths should be in proper proportion (approximately). Starting from rest_{1}, a car accelerates_{2} to its maximum velocity, maintains_{3} that velocity for a few seconds, and then brakes_{4} as quickly as possible, finally returning to rest_{5}.

Class
33:
Wednesday
1/13/2021 Warm Up: A 50kg rower accelerates to our left at a rate of 1m/s^{2}. She does this by applying a 100N force to the oars. Draw all of the forces acting on the rower and calculate their magnitudes.

Class
32:
Tuesday
1/12/2021 Warm Up: A person pushes a box with a force of 21N, as shown. This causes the two boxes to accelerate. If there is no friction between the boxes and their sliding surface... 1. What is the "contact force" between the two boxes? 2. What are all of the individual forces and net forces that are acting on each box? 3. Compare and contrast this "contact force problem" with a "tension problem."

Class
31:
Monday
1/11/2021 Warm Up: Suppose a skydiver steps out of a stationary helicopter, falls until reaching terminal velocity, deploys a parachute, reaches a new terminal velocity, lands on the ground, and then stands still. [Skydiving physics video] Draw one force diagram for the beginning of this trip (t = 0s), another force diagram representing t = 2s, and new force diagram for every instance when the net force switches between positive, negative, or zero. Use labeled arrows to identify the individual and net forces, and use arrow length to show relative magnitude.
How many diagrams should you draw?

Class
30:
Friday
1/8/2021 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 "freefalling" cat? 5. Aside from the moment of impact, when does a falling cat experience maximum net force?

Class
29:
Thursday
1/7/2021 Warm Up: 1. Which can you throw with more force, a Wiffle Ball® (0.045kg), a baseball (0.145kg), or a bowling ball (6.3kg)? Or is there no difference? Explain your thinking. 2. What limits the amount of force that you can apply when you throw a light object, like a Wiffle Ball, or a feather? Interesting Link: article about the fastest pitch ever thrown

Class
28:
Wednesday
1/6/2021 Warm Up: If you need to stop a car quickly, why should you avoid locking the tires and skidding?

Class
27:
Tuesday
1/5/2021 Warm Up: From the homework... 15. According to Newton’s third law, each team in a tug of war pulls with equal force on the other team. What, then, determines which team will win?

Class
26:
Monday
1/4/2021 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?

Class
25:
Tuesday
12/22/2020 Warm Up: Santa Claus from an Engineer's Perspective

Class
24:
Monday
12/21/2020 Warm Up: None

Class
23:
Friday
12/18/2020 Warm Up: None

Class
22:
Thursday
12/17/2020 Warm Up: 1. 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? 2. 1m/s = ____ mph. For next week's test, memorize this or be able to calculate it based on a known conversion.

Class
21:
Wednesday
12/16/2020 Warm Up: Here are the problems we made up yesterday. Let's solve them.. 1. A projectile in freefall travels 5m horizontally and 20m vertically, in a time of 11s. What is its initial speed? 2. A second projectile has an inital y velocity of 2m/s. After 13 seconds of freefall, it hits a horizontal surface. At the moment of impact, its x velocity is 8.5m/s. At what angle does the projectile hit the horizontal surface?

Class
20:
Tuesday
12/15/2020 Warm Up: 1. What is an "asymmetric" projectile problem? 2. How many fundamentally different types of asymmetric trajectories (for a physics problem) can you think of? 3. What are some variables that can be incorporated into a nonsymmetric projectile problem? 4. Let's create a problem (or two). To give time for retakes, we can solve it (them) later.

Class
19:
Monday
12/14/2020 Warm Up: I usually solve simple (orthogonal) river problems by drawing a headto tail diagram of the component vectors and the resultant vector. For complicated (nonorthogonal) problems, I make a table of x and y components. Would a table work for simple problems, like number 1, below? 1. A river's current flows 5m/s southward. A boat on the river has a velocity of 7m/s westward. What is the boat's heading, and what is its speed relative to the water? Here's a trickier one... 2. A second boat, on the same river, has an eastward velocity and a northeastward heading. Find it's speed relative to the water and its speed relative to the Earth.

Class
18:
Friday
12/11/2020 Warm Up: 1. Two of the vectors A, B, and C add up to the third vector. Which is the resultant? 2. Point D lies on the curvy path followed by an object. How would we properly draw the object's V, Vx, and Vy at point D?

Class
17:
Thursday
12/10/2020 Warm Up: Use the Range Formula to solve the homework problem that I didn't assign.

Class
16:
Wednesday
12/9/2020 Warm Up: An airplane flying horizontally with a ground speed of 120 m/s releases a bomb from a height of 4,800 meters. If the bomb is not affected by air resistance, how far ahead of the target (in the x dimension) should the bomb be released? Assume that the bomb is in freefall once it is released.

Class
15:
Tuesday,
12/8/2020 Warm Up: Another way to identify the resultant vector... The resultant vector in a "river problem" is the vector that is dependent on all of the other vectors. Any one of the other vectors, if altered, would change the resultant vector. This is not true of the component vectors.
Which of the following is dependent on all of the other vectors  and is therefore the resultant vector? The captain of a blimp is following her compass, keeping the blimp on a Northward heading. A mouse, running across the running surface of a treadmill on the blimp, is traveling Eastward. The wind surrounding the blimp is blowing to the Southwest. The running surface of the treadmill is traveling Westward.

Class
14:
Monday,
12/7/2020 Warm Up: No warmup. No Google Meet. Begin the test right away.

Class
13:
Friday,
12/4/2020 Warm Up: No warmup. No Google Meet. Begin the test right away.

Class
12:
Thursday,
12/3/2020 Warm Up: Get your calculators out so that you can help me with this nonorthogonal river problem... A golf cart on an aircraft carrier is traveling with a velocity of 4m/s in a direction 32 degrees west of North, relative to the Earth. If the aircraft carrier's velocity is 6m/s, in a direction 10 degrees east of North, what are the golf cart's heading and speedometer reading? Video of solution

Class
11:
Wednesday,
12/2/2020 Warm Up: Vector A plus vector B gives the resultant vector C (vector sum). Find the magnitude and direction of vector B. 1) Estimate the answer graphically 2) Find the answer "analytically" (by reducing these vectors to their x and y components).

ClassClass
10:
Tuesday,
12/1/2020 Warm Up: Trig Review The figures on the right show two right triangles. What are the magnitudes of... 1. Arrow A? 2. Arrow B? 3. Arrow C? 4. Angle theta?

Class
9:
Monday,
11/30/2020 Warm Up: Mr. Chase suggested a way to separate motion into 9 categories, based on an object's velocity and acceleration. This categorization is based on the fact that Velocity can be +, , or 0, and acceleration can also be +, , or 0.
Considering the motion of a swinging pendulum in the x dimension... 1. Identify where in the video each of those 8 types of motion occurs. 2. Which type of motion is not demonstrated?

Class
8
Friday,
11/20/2020 Warm Up: Sketch motion graphs for a basketball that is dropped (starting from rest) onto a gym floor and allowed to bounce back up to the point where its velocity is zero. Create graphs for position, velocity, and acceleration vs. time. *For the acceleration graph, try to at least get the sign correct.

Class
7
Thursday,
11/19/2020 Warm Up: I never completed Example 2, from the Class 5 notes. Let's do it now... Helpful hints: 1) Draw a diagram, 2) Identify "separate events" (intervals with different accelerations and/or starting points and endpoints) 3) List commonlyused variables,

Class
6 Wednesday,
11/18/2020 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:

Class
5 Tuesday,
11/17/2020 Warm Up: In the physics world, an object is in "freefall" as long as gravity is the only force acting on that object. The object may freefall upward or downward. Near the Earth's surface, the acceleration of freefalling objects due to gravity is approximately 9.8m/s^{2}. Consider this scenario... At t = 0s, a ball is freefalling directly upward 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/s^{2} instead of g = 9.8m/s^{2}] Today:

Class
4
Monday, 11/16/2020 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. 3. Can you state a general rule (or some rules) for determining whether the object is speeding up or slowing down in this exercise? (i.e. speed increasing vs. speed decreasing) Today:

Class
3:
Friday,
11/13/2020 Warm Up:
A ball is thrown at the floor from a height of 4m.
It hits the floor and bounces back up to a height of 6m, where it
is caught. Assuming that the
entire round trip takes 2 seconds…
1. What is the total distance traveled by the ball on its round trip?
2.
3.
What is the ball's average velocity for this round trip? 4. What is the ball's average speed for this round trip?
Google Meet  Use the link in Google Classroom (or watch the recording later on the class YouTube channel). Just in case I mess up today's video, here's a video of the same notes from 2017.
Homework:

Class
2:
Thursday,
11/12/2020 Warm Up: 1. For each letter, describe what is happening to the person's speed and direction during the 10 seconds represented on the graph. 2. Does anyone have a theory regarding why the moon is brightest on each end of the blur (in the photo from last class)? Or did you click the link?
Today: Google Meet  Use the link in Google Classroom
Homework:

Class
1: Wednesday,
11/11/2020 Physics 200: Mr. Stapleton Warm Up: 1. How were the photos on the right created? 2. Suppose you attach a flashlight to a bicycle tire, as shown in the diagram. Then you ride the bicycle in complete darkness while some one takes a long exposure photo. What pattern will the flashlight make in the photo? Why?
Today: All Students  11:00 Google Meet  Use the link in Google Classroom
