A Police Cruiser Hunting for a Suspect Pulls Over and Stops

Short Answer

A police cruiser hunting for a suspect pulls over and stops at a point a = 10 ft from a straight wall. The flasher on top of the cruiser revolves at a constant rate of 75°/second, and the light beam casts a spot of light as it strikes the wall. How fast is the spot of light moving along the wall at a point 50 ft from the point on the wall closest to the cruiser?
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Round the answer to the nearest tenth, if necessary.
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__________ ft/sec