Question

A ball falling down vertically collides with a smooth and fixed inclined plane of inclination $\theta$ . If it moves horizontally just after the impact, the coefficient of restitution is:

• A. $ta{n}^2\theta$
• B. $co{t}^2\theta$
• C. $tan\theta$
• D. $cot\theta$

Answer 1

The correct option is A $ta{n}^2\theta$


Now, velocity before and after collision along the incline plane remains same,so
$vsin\theta =ucos\theta$ …..(i)
and
Co-efficient of restitution $e=\frac{usin\theta }{vcos\theta }$
$\Rightarrow e=ta{n}^2\theta$