When the police want to know how fast your car is going, they
shoot a "radar gun" at the car. The radar gun emits waves at
approximately 24.15 GHz. Those waves reflect off of your car and
are detected by the same "radar gun" that emitted them. The
detector can detect both frequency and intensity. Using concepts of
general physics, explain how the radar gun works. You probably want
to draw pictures, use an equation or two, and use words.