INTERACTIVE EXAMPLE
© Copyright, Department of Physics, University of Illinois at Urbana-Champaign

Electromagnetic Waves I


A police car on the side of the road (at rest) uses a radar gun to catch speeders as they approach it. The frequency the radar gun emits is 8 x 109 Hz and the speed limit is 65 mi/hr. What is the difference in frequency of the emitted and returned radar wave? (A positive answer means the returned wave has a greater frequency than the emitted wave; a negative answer means the returned wave has a smaller frequency than the emitted wave.)

freturned - femitted = Hz