Class
42:
Friday,
1/13/23 Warm Up: Describe the motion of an object that has... 1. Positive velocity and negative acceleration 2. Negative velocity and negative acceleration 3. Zero velocity and positive acceleration
Today:
Homework:
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Class
41:
Wednesday,
1/11/23 Warm Up: 1) Find the force of drag in the situation on the right. 2) How did you do it?
Today:
Homework:
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Class
40:
Monday,
1/9/23 Warm Up: Match each graph with all of the other graphs that can represent the same motion.
Today:
Homework:
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Class
39:
Thursday,
1/5/23 Warm Up: The photograph on the right shows a homemade "Gauss Gun." In the picture there are 9 steel spheres and 4 cube-shaped magnets. The operator is preparing to roll one sphere toward a magnet. What will happen, and how will it work? Today:
Homework:
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Class
38:
Tuesday,
1/3/23 Warm Up: How can an understanding of momentum help you turn a towel into a better whip? Today: Homework:
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Class
37:
Wednesday,
12/20/22 Warm Up: 1. 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 2. What happens at 4:26 this afternoon?
Today:
Homework:
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Class
36:
Monday,
12/19/22 Warm Up: 1. Here's the impulse formula. What does it mean? 2. This picture shows a man who jumped from 2,500 feet with no parachute, but he is wearing a squirrel suit. Can you guess how he managed to land safely? Specifically, how can we explain the safe landing in terms of impulse (Ft)? Watch this video for the answer!
Today:
Homework:
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Class
35:
Thursday,
12/15/22 Warm Up: 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 change in its momentum, the dart or the board? Or do they experience the same change? 3. Can we understand these better with an IF (Initial/Final) chart? Today:
Homework:
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Class
33:
Tuesday,
12/13/22 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. Why does this happen?
Today:
Homework:
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Class
32:
Friday,
12/9/22 Warm Up: How does a Newton Cradle work? What's the point?
Today:
Homework:
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Class
31:
Wednesday,
12/7/22 Warm Up: How does NASA simulate weightlessness? Are the people in the video really weightless? Are astronauts in a space station weightless?
Today:
Homework:
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Class
30:
Monday,
12/5/22 Warm Up: The picture on the right shows a sequence of events experienced by a bungee jumper. The blue arrows and letters indicate velocity. Draw a diagram showing all of the individual force, and the net force, acting on the bungee jumper for each lettered moment in the sequence. Also show the jumper's acceleration.
Today:
Homework:
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Class
29:
Thursday,
12/1/22 Warm Up: A spool car is wound up and released. When the rubber band unwinds fully, a pin pops out, allowing the car to keep rolling. 1) What forces are acting on the car while the rubber band is pushing it? 2) What forces are acting on the car after the rubber band stops pushing, but before it stops rolling? 3) If we wind the rubber band more, which of those forces will change? How? 4) How can we calculate those forces?
Today:
Homework:
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Class
28:
Tuesday,
11/29/22 Warm Up: If you need to stop a car quickly, why should you avoid locking the tires and skidding? Today:
Homework:
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Class
27:
Friday,
11/18/22 Warm Up: How can you create a nice scan of a drawing to insert in your slideshow? Today:
Homework:
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Class
26:
Wednesday,
11/16/22 Warm Up: Two identical triplets weigh 700N each. They are both standing on properly-functioning bathroom scales in elevators (different elevators). One bathroom scale reads 600N. Another reads 700N. The third reads 800N. 1. What does the reading on a bathroom scale always tell you? 2. What is going on here? Why do the scales have different readings? Today:
Homework:
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Class
26:
Monday,
11/14/22 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:
Homework:
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Class
25:
Thursday,
11/10/22 Warm Up: According to Newton's 3rd Law, every force has an equal and opposite force. So how do you win a game of tug-of-war? Today:
Homework:
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Class
24:
Tuesday,
11/8/22 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:
Homework:
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Class
23:
Friday,
11/4/22 Warm Up: This 50kg rower has an acceleration of -1m/s2. She is pulling against the oars with a force of 100N. Draw and calculate all of the forces acting on the rower. Today:
Homework:
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Class
22:
Wednesday,
11/2/22 Warm Up: 1. How fast does chalk fall? Is it faster than a cat?... My spreadsheet answer 2. Sometimes people celebrate special occasions by firing guns into the air. Is this safe? 3. Why don't clouds fall out of the sky? Calculated terminal velocities of various spheres. Today:
Homework:
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Class
21:
Monday,
10/31/22 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.”
Can you explain this surprising finding?
Today:
Homework:
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Class
20:
Thursday,
10/27/22 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:
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Class
19:
Tuesday,
10/25/22 Warm Up: Why can't you pick yourself up? Today:
Homework:
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Class
18:
Friday,
10/21/22 Warm Up: What will happen if I poke a knife through a potato, hold both objects in the air with the knife pointing downward, and then hammer the butt of the knife into the potato? Why? What if it's an apple, because I didn't have potatoes? Today:
Homework:
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Class
17:
Wednesday,
10/19/22 Warm Up: None Today:
Homework:
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Class
16:
Monday,
10/17/22 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:
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Class
15:
Thursday,
10/13/22 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:
Homework:
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Class
14:
Tuesday,
10/11/22 Warm Up: No warm-up today. Star reader and then the test. Today:
Homework:
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Class
13:
Wednesday,
10/5/22 Warm Up: Go to this web page on your chromebook and open up the video segment where I am explaining how to do number 17 on the practice test. Today:
Homework:
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Class
12:
Monday,
10/3/22 Warm Up: How should you study for Tuesday's test? Today:
Homework:
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Class
11:
Thursday,
9/29/22 Warm Up: Consider the case of this ball. At t = 0s, the ball is flying 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. Let's assume that there is no air resistance and that g = 10m/s2.
Today:
Homework:
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Class
10:
Tuesday,
9/27/22 Warm Up: A unit conversion problem... 1. How old is someone who has lived a billion seconds? Have you lived that long? 2. What is the significance of 1 billion heartbeats?
Today:
Homework:
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Class 9:
Friday,
9/23/22 Warm Up: If you throw a ball straight up with a velocity of 10mph... 1. What's its velocity at the highest point? 2. What's its velocity just before it returns to your hand? Today:
Homework:
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Class 8:
Wednesday,
9/21/22 Warm Up: The world record rubber band car traveled this 5m distance in 2.82 seconds. What was its average velocity? Today:
Homework:
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Class 7:
Monday,
9/19/22 Warm Up: Velocity and Acceleration Combinations Matching Quiz. Use this link to take the quiz, or take it in Google Classroom. Today:
Homework: |
Class
6:
Thursday,
9/15/22 Warm Up: What is a spool car? How does one work? Today:
Homework:
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Class 5:
Tuesday,
9/13/22 Warm Up: Suppose a pendulum is allowed to swing back and forth from left to right (and back). At what points in the pendulum's motion does it have these combinations of velocitya and acceleration? Today:
Homework: Complete the position graphs on p.8-9 of the Unit 1 Packet (PDF). Answer Key |
Class
4:
Friday,
9/9/22 Warm Up: Suppose you want to record the motion of a cart (1) moving on a track (2), using a motion detector (3). Your goal is to produce a graph with positive velocity and zero acceleration. You can use few books (4) and a computer (5) to do this. How can you do this? Today:
Homework: Complete the acceleration graphs on p.8-9 of the Unit 1 Packet (PDF). Answer Key |
Class
3:
Wednesday,
9/7/22 Warm Up: 1) Suppose you want to walk in front of a motion sensor and produce the velocity graph shown here. How do you do it? 2) What would a graph of your position vs. time look like? Today:
Homework: Complete #2 on page 8 of the Unit 1 Packet (PDF). Just draw the velocity graph. Here's the video from class showing how we did this with a graph on page 7. |
Class
2:
Friday,
9/2/22 Warm Up: The graph on the right shows the positions at different times for seven different people, relative to a motion detector at the 0m mark. Which person (people) was (were)...
Today:
Homework:
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Class
1:
Wednesdsay,
8/31/22 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:
Homework: If you didn't finish the motion matching questions (Unit 1 Packet, page 1), finish them before next class. Answer Key
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