# A sphere of mass m moving horizontally $V_0$ collides against a pendulum bob of mass m. If the two masses stick together after the collision then the maximum height attained is

$\begin {array} {1 1} (a)\;\frac{V_0^2}{2g} & \quad (b)\;\frac{V_0^2}{4g} \\ (c)\;\frac{V_0^2}{6g} & \quad (d)\;\frac{V_0^2}{8g} \end {array}$

momentum before collision = momentum after collision
$mV_0=2mV$
$V= \large\frac{V_0}{2}$
By energy conservation
$\large\frac{1}{2}$$(2m) \bigg (\large\frac{V_0}{2}\bigg)^2$$=2mgh$
$h= \large\frac{V_0^2}{8g}$