When a moving spaceship emits regularly-spaced flashes of light, how frequently you see the flashes depends on the ship
A)approaching you.
B)receding from you.
C)either of these
D)none of these

Question

Quizplus · Accepted Answer

The frequency of the flashes of light depends on the relative motion between the spaceship and the observer. If the spaceship is approaching the observer, the frequency will appear to increase (blue shift). If it is receding, the frequency will appear to decrease (red shift). Therefore, the frequency depends on both the motion of the spaceship and the observer, and either of these scenarios can occur.

When a Moving Spaceship Emits Regularly-Spaced Flashes of Light, How