Question

Two fixed navigation beacons mark the approach lane to a star. The beacons are in line with the star and are 65 Mm (1 Mm = 10^6 m) apart. A spaceship approaches the star with a relative velocity of 0.90 c (with respect to the star) and passes the beacons. As the ship passes the first beacon the ship emits a short radar pulse toward the second beacon, and the radar echo is received at the ship. The time interval between the emission of the the radar pulse and the reception of the radar echo is closest to:

A) 60 ms B) 520ms C) 99ms D) 230 ms E) 150 ms

Answer 1