You don\'t have to show your work i just need to compare the answers you get wit

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You don't have to show your work i just need to compare the answers you get with the answers that i got to see if i'm right.

1. Why do you land with your knees bent when you jump off a tall chair? A. To reduce your change in velocity of your body. B. o increase the interaction time on your bones C. To increase the stopping force 2. The momentum of a system may be conserved even when the mechanical energy is not. This statement is A. true B. false 3. All inelastic collisions imply that the objects stick together. This statement is A. true B. false 4. A bowling ball traveling with a speed v collides with a ping-pong ball moving at a speed v, but in the opposite direction. One can conclude that the magnitude of the impulse imparted to the ping-pong ball is A. less that that of the bowling ball B. greater than that of the bowling ball C. the same as that of the bowling ball. 5. A car of mass m, traveling at speed v, stops in time t when maximum braking force is applied Assuming the braking force is independent of mass, what time would be required to stop a car of mass 2m traveling at speed v A. C. 12t D. 2t E. 4t 6. Net Impulse is best related to A. momentum B. change in momentum C. kinetic energy D. change in kinetic energy E. none of the above 7. Two carts are held together. Cart 1 is more massive than Cart 2. As they are forced apart by a compressed spring between them, which of the following will have the same magnitude fo both carts. A. acceleration B. change of velocity C. force D. speed E. velocity f the unit for force is F, the unit for velocity is v and the unit for time t, then the unit for momentum is C. Ft?v A. Ft B. Ftv D. Ft/v E. Fvlt 9. A certain particle undergoes erratic motion. At every point in its motion, the direction of the particle's momentum is ALWAYS A. the same as the direction of its velocity B. the same as the direction of its acceleration C. the same as the direction of the net force D. the same as the direction of the kin energy vector etic E. none of the above

Explanation / Answer

If you jump off a table, as your feet hit the floor, you let your legs bend at the knees in order to mimimize the force applied to your skeletal system. Just before you reach the floor your body has momentum. After you land, your body will have no momentum, so therefore there was a change in momentum and an impulse was necessary for this to happen.

The impulse on your body in this case comes from the floor and the size of the impulse is constant. Since impulse is the product of the force and the time over which it acts, then force and time are inversely proportional

. So, if the force acts over a longer time period, then it will have a smaller magnitude. If we didn't bend our knees, the force would act over a much shorter period of time and would thus be much greater in magnitude, great enough to break our bones.

option (B) is correct answer

(2)

True

in an inelastic collision , momnetum is conserved but mechanical energy not

(3)

true

(4)

impulse is nothing but change in momentum

momentum of the ping ball increases so impulse of ping pong ball is gretar than that of bowling ball

option(B) is correct answer

As per guide lines I worked first four question, please post remaning questions in the next post

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