Question

A moving billiard ball hits another ball at rest, causing the first ball to stop moving as the second rolls away. If the two balls have the same mass, what is the relationship between them?
The momentum of the second ball would be greater than the original momentum of the first ball.
The momentum of the second ball will be less than the original momentum of the first moving ball.
The momentum of the second ball will equal to the original momentum of the first moving ball.
The momentum of the second ball will depend on the acceleration of the first moving ball.

Answer 1

Answer:

The momentum of the second ball will equal to the original momentum of the first moving ball.

Explanation:

Let m be the mass of both billiard balls. Initially, the first ball is moving at speed u and the second ball is at rest. After the collision the second ball moves with a velocity v

Using the law of conservation of momentum, we can write

The momentum before collision = The momentum after collision

mu + m(0) = m(0) + mv

mu = mv

Initial momentum of first ball = final momentum of second ball

Answer 2

The momentum of the second ball will depend on the acceleration of the first moving ball.