Imagine the speed of light in another universe to beonly 100 m/s. Two cars are traveling along an interstatehighway in opposite directions. Person 1 is traveling110 km/h, and person 2 is traveling 140 km/h.How fast does person 1 measure person 2 to be traveling?How fast does person 2 measure person 1 to betraveling?
42. A train traveling very fast (v =0 .6c) has an engineer (E) at the front, a guard (G) at the ▯ rear, and a passenger (S ) exactly halfway 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 Sis 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 ans: A 43. A console lamp in the cabin of a spaceship appears green when the ship and observer are both at rest on Earth. When the ship is moving at 0.90c away from Earth, passengers on board see: A. nothing (the frequency is too high to be seen) B. nothing (the frequency is too low to be seen) C. a red lamp D. a violet lamp E. a green lamp ans: E 44. A spectral line of a certain star is observed to be “red shifted” from a wavelength of 500nm to a wavelength of 1500nm. Interpreting this as a Doppler eﬀect, the speed of recession of this star is: A. 0.33c B. 0.50c C. 0.71c D. 0.8c E. c ans: D 45. A source at rest emits light of wavelength 500nm. When it is moving at 0.90c toward an observer, the observer detects light of wavelength: A. 26nm B. 115nm C. 500nm D. 2200nm