Question

A billiard ball (ball #1) moving at 5.00 m/s strikes a stationary ball (ball #2) of the same mass. after the collision, ball #1 moves at a speed of 4.35 m/s. find the speed of ball #2 after the collision.

Answer 1

Answer

Two billiard balls of equal mass are on a level, frictionless surface. The first ball is moving and collides with the second ball, which was stationary. After the collision, both balls are moving. What is a possible speed for the first ball after the collision? Need help

Explanation:

please

Answer 2

If it is completely elastic, you can calculate the velocity of the second ball from the kinetic energy 
v1 = velocity of #1 
v1' = velocity of #1 after collision 
v2' = velocity of #2 after collision. 

kinetic energy: v1^2 = v1' ^2 + v2' ^2 (1/2 and m cancel out) 
5^2 = 4.35^2 + v2' ^2 
v2 = 2.46 m/s <--- ANSWER