You observe a distant galaxy apparently moving away at 1/3 the speed of light (v c/3).If you could measure the speed that this galaxy's light is passing the Earth,you would get:
A)c/3
B)2c/3
C)c
D)4c/3
E)5c/3

Question

Quizplus · Accepted Answer

The speed of light is always constant in vacuum and is independent of the motion of the observer or the source of light. Therefore, the speed at which the light of the distant galaxy is passing the Earth would still be the speed of light, which is denoted by 'c'. The apparent motion of the galaxy away from the Earth is not related to the speed of light.

You Observe a Distant Galaxy Apparently Moving Away at 1/3