Question

in a game of billiards, a cue ball hits a stationary 8 - ball and then stops moving after the collision. if the momentum is conserved, what is the final momentum of the cue ball? (1 point)
it is less than its initial momentum but greater than zero.
it is zero.
it is greater than its initial momentum.
it is equivalent to the final momentum of the 8 - ball.

Explanation:

Momentum is calculated as \(p = mv\) (where \(p\) is momentum, \(m\) is mass, and \(v\) is velocity). After the collision, the cue - ball stops moving. When an object stops moving, its velocity \(v = 0\). Substituting \(v = 0\) into the momentum formula \(p=mv\), we get \(p = m\times0=0\). The fact that momentum is conserved (total momentum of the system before and after the collision is the same) is a general condition for the collision, but for the specific case of the cue - ball's final momentum, we only need to consider its own velocity after the collision.

Answer:

It is zero.