A light ray `I` is incident on a plane mirror `M`.The mirror is rotated in the direction as shown in
Channel: Doubtnut
Date: 2020-08-16

A light ray `I` is incident on a plane mirror `M`.The mirror is rotated in the direction as shown in the figure by an arrow at frequency `(9)/(pi) "rev"//"sec"`,The light reflected by the mirror is received on the wall `W` at a distance `10m`from the axis of rotation .When the angle of incidence  becomes `37^(@)`find the speed of the spot (a point) on the wall?