Billiard Ball Collision
Classical Mechanics
Level
1
Two billiard balls of the same mass collide elastically. 1/4 of the momentum from Ball A is transferred to Ball B, which was initially at rest. Which ball experiences an impulse of greater magnitude?
The magnitudes are the same
Ball B
Ball A
Cannot be determined
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
Impulse is the change in momentum, J = Δ p . If the momentum of Ball A before the collision is p i , then Ball A loses 1/4 of that momentum, and Ball B gains 1/4, so
J A = Δ p A = − p i / 4
J B = Δ p B = p i / 4 .
The opposite signs mean the impulses are in opposite directions, but the magnitudes are both p i / 4 .