# A sphere of mass m moving with constant velocity hits another stationary sphere of the same mass. If 'e' is the coefficient of restitution, then the ratio of velocities of the two spheres after the collision will be :

$\begin {array} {1 1} (1)\;\large\frac{1}{e} & \quad (2)\;\large\frac{1-e}{1+e} \\ (3)\;\large\frac{e}{1+e} & \quad (4)\;\large\frac{e+1}{e} \end {array}$

Ans : (2)
$\large\frac{1-e}{1+e}$