A train traveling very fast (v = 0.6c) has an engineer (E) at the front, a guard (G) at the rear and an passenger (S') exactly half way between them. Both E and G are equipped with yellow signaling lamps. The train passes a station, closely observed by the station master (S). Both E and G use their lamps to send signals. According to both S and S' these signals arrive simultaneously at the instant S' is passing S. According to S, the signal from E will look ______ and that from G will look _____:
A) red, blue
B) yellow, yellow
C) blue, red
D) blue, blue
E) red, red

Question

Quizplus · Accepted Answer

According to the Doppler effect, the light from the front of the train will be blueshifted, while the light from the rear of the train will be redshifted.

A Train Traveling Very Fast (V = 0