Rotating Mirror Light Speed Measurement · CAP 2025 #14
Physics · optics
Problem
A beam of light is directed towards an 8-sided rotating mirror. After getting reflected by one of the sides, light travels to a fixed mirror 60 km away, and reflects back to the rotating mirror. What is the minimum frequency of rotation of the mirror at which the light beam reflects along the original direction and reaches the detector?
A. 300000 rpm
B. 75000 rpm
C. 37500 rpm
D. 18750 rpm