Question

A glass ball, ball A, of mass 6.0 g moves at a velocity of 19.0 cm/s. It collides with a second ball, ball B, of mass 9.0 g, moving along the same line of velocity of 11.0 cm/s. After the collison, ball A is still moving, but with a velocity of 8.0 cm/s. a) What was ball A's original momentum? What is ball A's change in momentum? c) What is ball B's change in momentum? d) What is the momentum of ball B after the collison? e) What is ball B's speed after the collison?

Answer 1

Linear momentum is conserved. Whatever the momentum A lost in the collision, B gained.

I will be happy to critique your thinking.

Answer 2

Ball A's original momentum is .00114 kgm/s. The change in Ball A's momentum would be .006 kg x (.19 - .08) m/s, correct? Ball B's change in momentum would be .009 kg x (.11 - v) m/s. The momentum of Ball B would be .009 x the change in velocity from the previous question. Ball B's speed would be the original velocity minus the change in velocity.

Answer 3

Ball A's original momentum is .00114 kgm/s. The change in Ball A's momentum would be .006 kg x (.19 - .08) m/s, correct? Ball B's change in momentum would be .009 kg x (.11 - v) m/s. The momentum of Ball B would be .009 x the change in velocity from the previous question. Ball B's speed would be the original velocity minus the change in velocity.

Answer 4

Correct on the change of A momentum.

Ball B change in momentum is equal to the change in A momentum, not the change in A velocity.

New Ball B momentum:
.009*.11+ .006(.19-.08)
From that, you determine B velocity (by dividing the Momentum my mass B)