Problem 1. In the distant future, a physics student is rushingto her final exam traveling in a spaceship at relativistic speed.She passes a policeman at rest a distance 9 km from a trafficsignal (measured in his rest frame).
a) The policeman monitors the student’s tail lights (red lightwith λ=650 nm in her rest frame) with a spectroscope, viewingdirectly along her motion away from him. He observes a wavelengthλ=1300 nm (infrared). What is her speed relative to thepoliceman?
b) How long, according to her, does it take to reach the trafficsignal?
c) When the policeman stops her for running a red light sheclaims that she saw the traffic signal as green (i.e., λ=520 nm).Compute the wavelength she would have seen. Is she telling thetruth?