• # question_answer Two smooth objects with a coefficient of restitution e, collides directly and bounce as shown :- just before impact just after impact   Newton's law of restitution gives:- A)  ${{v}_{1}}=3\,eu$B)  $u=3\,e{{v}_{1}}$C)  ${{v}_{1}}=2\,eu$                                         D)  It cannot be applied as the masses are not known

$e=\frac{velocity\,\,of\,\,separation}{velocity\,\,of\,approach}$ $\Rightarrow$  $e=\frac{{{v}_{1}}-2{{v}_{1}}}{3u-6u}=\frac{{{v}_{1}}}{3u}$ $\Rightarrow$${{v}_{1}}=3eu$