## Question

A small plane mirror is rotating at a constant frequency of *n* rotations per second. With what linear velocity (in ms^{–1}) will a light spot move along a spherical screen of radius of curvature of *R* metres if the mirror is at the centre of curvature of the screen?

### Solution

If a mirror rotates through an angle θ, the image rotates through an angle 2θ. Therefore, the linear speed of the light spot is

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#### SIMILAR QUESTIONS

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