Engineer a Shoe -
Extension on Momentum
Warm-up Question:
Is this plausible or implausible?
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Argue from Evidence
that both of these outcomes are possible
Object | Before Collision | After Collision |
Left cherry | mass = 0.2 kg velocity = 2 m/s | mass = 0.2 kg velocity = 0 m/s |
Right cherry | mass = 0.2 kg velocity = - 2 m/s | mass = 0.2 kg velocity = 0 m/s |
small water drop (#1) on left cherry | mass = 0.01 kg velocity = 2 m/s | mass = 0.01 kg velocity = 2 m/s |
big water drop (#2) on right cherry | mass = 0.03 kg velocity = -2 m/s | mass = 0.03 kg velocity = -2 m/s |
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Quiz Question:
Choose at least two objects from the table 1 below (and shown in the movie clip) and construct an argument if their interaction is plausible or impossible?
Claim. Evidence. Reasoning.
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Object | Before Collision | After Collision / Before Rescue | After Rescue |
White Truck | mass = 10000 kg velocity = 20 m/s | mass = 10000 kg velocity = 0 m/s | |
Black Truck | mass = 10000 kg velocity = -20 m/s | mass = 10000 kg velocity = 0 m/s | |
Morpheus (in all black) | mass = 100 kg velocity = 20 m/s | mass = 100 kg velocity = 20 m/s | mass = 100 kg velocity = 0 m/s* (left/right) |
Key Master (white shirt) | mass = 60 kg velocity = 20 m/s | mass = 60 kg velocity = 20 m/s | mass = 60 kg velocity = 0 m/s* (left/right) |
Neo (guy flying) | mass = 70 kg velocity = 200 m/s | mass = 70 kg velocity = 200 m/s | mass = 70 kg velocity = 0 m/s* (left/right) |
*midair stops and starts flying upwards at 10 m/s
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Below are slides for the question “How does anything ever stop?” and 2D and 3D collisions.
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Wait! How then, does anything ever stop?
MVbefore+ mvbefore = MVafter+ mvafter
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Spiraling Back
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How then does anything ever stop?
MVbefore+ mvbefore = MVafter+ mvafter
So if:
MVbefore+ mvbefore = MVafter+ 0
You can only stop as much as you give your momentum to something else!
or ?
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MVbefore+ mvbefore = 0
Warm-up Question:
Imagine two years into the future and you are taking IB Physics with Mr. Hill. On the bus ride over to Reed College to see a nuclear reactor with your own eyes, Mr. Hill ask you to throw him his frisbee at 5 m/s. Ms. Downey is on the sidewalk, would she see the frisbee going the same speed, faster or slower?
How would you have to throw it so Ms. Downey see the frisbee stand still?
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This is even true in 2 and 3 Dimensions
*Note: no one was hurt
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