Tuesday, July 2, 2013

Unit 7: Momentum, impulse and collisions

Today we worked more on momentum. We learned that momentum always wants to go in the same direction and stopping momentum takes more force. In the picture above we did a lab using the air track two carts, and a photogate to measure velocity. We used a nerf gun to hit the cart and push it through the photogate, so we could find the velocity of the whole system, which is the carts and the dart all together. From that we could find the cart/dart final velocity and total momentum. We coud also find the initial velocity for both the carts and the dart. To do this we used a series of equations, like Change in momentum is equal to force x time, which is equal to mass x change in velocity. This lab also helped us understand how momentum is conserved.

Today we also worked on word problems with impulse and collisions. The more mass an object has, not only does it has less acceleration, but the object will have less momentum. To reduce impulse (change in momentum), you have to decrease the contact time. We also learned that the area under the curve of a Force vs. TIme graph is the impulse.

2 comments:

  1. Oh yeah, I was in both your Unit 7 pictures. I'm cool. You explained the lab clearly as well as all the stuff we could find with only what we knew from the lab. While we didn't do much stuff today that requires writing about, you managed to write down all the important stuff we did today, so good job!!

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  2. What gorgeous people doing that lab. I agree with Joy, your explanation of the lab was wonderful and very clear. However, I'm still kinda confused about impulse, but I think that, in order to reduce impulse, you have to reduce the contact time while either maintaining the same force, or decreasing force as well. You probably meant that, anyways. Really good post. :)

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