The radar gun of police car emits microwaves having a frequency of f1= 7.50 GHz. The beam reflects from a speeding car, which is moving in the direction of the police car at 48.0m/s with respect to the police car. The speeder's radar detector detects the microwave at a frequency f2.
i) Determine which is larger f1 or f2?
ii) Determine the frequency difference f2- f1.