A radar trap operates at a frequency of f=10GHz. The speed of microwaves is v=3.0*10^8 m/s. The microwave beam is aimed at a car approaching at 72km/hr (20m/s).
a) Calculate the difference between the observed frequency, f0, at the car and the original frequency, fs.
b) The car becomes a moving source at frequency f0. Calculate the frequency difference between the reflected signal and fs.
c) When the reflected signal is combined with the original signal, a beat frequency is produced. What is its frequency?