College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 49

A pulsar is a stellar object that emits light in short bursts. Suppose a pulsar with a speed of 0.950 c approaches Earth, and a rocket with a speed of 0.995 c heads toward the pulsar. (Both speeds are measured in Earth's frame of reference.) If the pulsar emits 10.0 pulses per second in its own frame of reference, at what rate are the pulses emitted in the rocket's frame of reference