Question

A ball of mass 625.g traveling 4.00 m/s to the right, has an elastic head-on collision with an identical ball which is at rest. Find the final velocity of each ball.

Answer 1

Given:

$m_1=m_2=625\:\rm g$

$v_1=4.00\;\rm m/s$

$v_2=0\;\rm m/s$

The final velocities of balls

$$v_1'=\frac{m_1-m_2}{m_1+m_2}v_1=0\:\rm m/s$$

$$v_2'=\frac{2m_1}{m_1+m_2}v_1=v_1=4.00\:\rm m/s$$