Question

A ball of mass m and speed v travels horizontally, hits a wall, and rebounds with the same speed as it had before the collision. Determine the magnitude of the ball's change in momentum as a result of the collision.

Answer 1

Answer:2mv

Explanation:

Given

Ball travelling with speed v hits the wall and rebound with same speed

Initial momentum of ball is $P_i=m\cdot v$

Momentum after the collision is $P_f=m\cdot (-v )$

Change in momentum is $\Delta P=P_i-P_f$

$\Delta P=mv-(-mv)$

$\Delta P=2mv$

Therefore magnitude of change in momentum is $2 mv$  

Answer 2

Answer: (MbxUb) + MbVb)= M( V+U). Where U=0, initial velocity.

It can be express as M1V1=M2V2.

Meaning momentum before collision is equal moment after collision.

Explanation:

If the ball returns with the same speed, definitely there will be no loss in the kinetic energy, so it returns with the same momentum before the impact.