Slick Willy is in traffic court (again) contesting a $50.00 ticket for speeding. The speed limit was vo-50 mph, and the police officer clocked slick going vsw = 74 mph. However, he was caught by a police officer driving towards him, so he is arguing that although the police officer measured him to be speeding, in reality he was not. Slick Willy is assuming that the Doppler shift in electromagnetic radiation is described in the same way as the Doppler shift for sound. But note that the speed of electromagnetic radiation in air is about c 3.0x 108 m/s, considerably faster than the speed of sound in air 25%.

Part (a) If the cop had been stationary, and assuming the radar gun operates at a frequency offe-18.3 GHz, enter an expression for the frequency, f, of the electromagnetic wave that would have returned to the police car, in terms of the defined quantities Grade Sum Deductions Potential 0% 100% Submissions Attempts remaining: 5 (5% per attempt) detailed view 0 Submit Hint I give up! Feedback: 1% deduction per feedback Hints: 1 % deduction per hint. Hints remaining: 3 25%.

Part (b) Now take into account the motion of the police officer toward slick willy at a speed of vP0. Assume Slick Willy was indeed moving toward the police officer at the speed limit of vo. Enter an expression for the frequency, f, of the electromagnetic wave that would have then returned to the police car, in terms of the defined quantities 25%.

Part (c) The police officer confirms that she measured that frequency, f. Enter an expression, in terms of the other defined speeds, for the speed at which the police car must have been moving if Slick Willy were actually driving at the speed limit. To do that, equate the expressions you entered in parts (a) and (b) and solve for vPO. Make use of the low-speed approximation (1 ± v/c)" 1 ± nvic for lvl << c. 25%.

Part (d) Calculate how fast, in miles per hour, the police car must have been moving in order for Slick Willy to have been going at the speed limit.