A billiard ball moving with a speed of `5 m//s` collides with an identical ball, originally at rest. If the first ball stop dead after collision, then the second ball will move forward with a speed of:

Options

A. `10 m//s`
B. `5 m//s`
C. `2.5 m//s`
D. `1 m//s`

Answer

B

Explanation

It is a case of elastic collision. As masses to two balls and equal and `2^(nd)` ball is at rest before collision, hence after the collision the speed are just exchanged, i.e., `1^(st)` ball will now come to rest while the second ball will move forward with the same speed as that of the first , i.e., `5 ms^(2)`