Physics

Problem

A ball of mass

0.4\,\text{kg}

moving at

8\,\text{m}\,\text{s}^{-1}

overtakes another ball of mass

0.2\,\text{kg}

moving in the same direction at

2\,\text{m}\,\text{s}^{-1}

. After collision the speeds along the same line become

4\,\text{m}\,\text{s}^{-1}

for the first ball and

6\,\text{m}\,\text{s}^{-1}

for the second. Determine the coefficient of restitution for the impact.