Question

A particle is projected at point $A$ from an inclined plane with inclination angle $\theta$ as shown in figure. The magnitude of projection velocity is $\overrightarrow{u}$ and its direction is perpendicular to the plane. After some time, it passes from point $B$ which is in the same horizontal level of $A$, with velocity $\overrightarrow{v}$. Then the angle between $\overrightarrow{u}$ and $\overrightarrow{v}$ will be:

Answer 1

$\alpha ={180}^{\circ }-2\theta$

Final Answer: $\left(c\right)$