Question

5 The astronaut travelling at 86.7% the speed of light (γ = 2) has an “atomic clock” based on excited atoms that emit pulses of light at a rate of 20,000 pulses per second. A stationary observer on Earth measures the clock ticking at a rate of

a. 10,000 pulses per second.

b. 40,000 pulses per second.

c. 20,000 pulses per second.

d. the speed of light.

Answer 1