Problem

A projectile is projected with speed

u

at an angle of

60^\circ

with horizontal from the foot of an inclined plane. If the projectile hits the inclined plane horizontally, the range on inclined plane will be a.

\frac{u^2 \sqrt{21}}{2g}

\frac{3u^2}{4g}

\frac{u^2}{2g}

\frac{\sqrt{21} u^2}{8g}