Virginia, Virginia, if you look closely at the scale on your velocity graph, you’ll see that it isn’t travling at 0m/s when it is at the bottom of the graph (your scale doesn’t start at 0). I also don’t see how you got the initial velocity of the car to be 15m/s for the initial [...]

Angular momentum is the mass of the object times the angular velocity times the radius. Angular velocity would be the rate of change of angular displacement of an object. It could be measured by the fraction of the circumference of the circle that encompasses the distance traveled divided by the time it takes to travel [...]

this is done.

Also, I see that it my my error in my previous comment that said the velocity was 65 m/s. I’m sorry about that. I was typing too fast. The actual maximum velocity in m/s is 29 m/s. Again, I think you should be able to fix your graph with just a few minutes of work.

Sarah, I think you’ve got some physics problems in your analysis/graph you still need to resolve. The maximum velocity of the ride is 65 mi/h, not m/s. This is why the value you got for the distance the ride falls is way too high (225 m is taller than anything in the park). Also, I [...]

Noah, It would be very hard for a reader not familiar with your work to understand at all what you are doing here. Can you add explanations, 1-2 sentences to each calculation so that someone can understand your work? Also, now that you have an impulse, you should estimate a time for the collision (does [...]

Andrew, great work so far. I do think to finish this off, I’d like to know about the force required to slow you down. 5.8m does seem like a reasonable distance for you to slow down.

Andrew, I think you might need to be a bit more careful in accounting for signs here. When the basketball hits the gound, the sign of the momentum should change from negative to positive. This is the key to what’s going on with the tennis ball. It isn’t bouncing off of a stationary wall, it’s [...]

Excellent work. This is finished. But I wonder what force is required to break an egg?

Naman,
Nice work. This is complete. Feel free to test it with the loop in our classroom.

I think your are basically done. But I think you’ve got a bit of misunderstanding about impulse. You’ve calculated the speed right before it hits the pillow. Now you need to calculate the change in momentum to bring it to rest. This is the impulse that the catcher must provide. You are right that impulse [...]

Sarah, I don’t think you need to find energies here. Here’s what I think you need to do to finish this off. It would be very interesting to draw a velocity vs time graph for this ride. There’s a bit of info I gleaned from the wikipedia entry : it takes 3.5 seconds for the ride to [...]