Problem

A small plane mirror is placed at the centre of a spherical screen of radius

R

. A beam of light is falling on the mirror. If the mirror make

n

revolutions per second, the speed of the spot of light on the screen after reflection from the mirror will be (a)

\frac{nR}{2\pi}

(b)

\frac{nR}{4\pi}

(c)

2\pi nR

(d)

4\pi nR