Suppose that Hubble's constant were 20 kilometers per second per million light- years. How fast would we expect a galaxy 100 million light- years away to be moving? (Assume the motion is due only to Hubble's law.)
A)away from us at 2,000 km/s
B)away from us at 20,000 km/s
C)away from us at 200 km/s
D)toward us at 2,000 km/s

Question

Quizplus · Accepted Answer

Hubble's Law states that the velocity at which a galaxy moves away from us is directly proportional to its distance from us. Using the given Hubble's constant of 20 km/s per million light-years, a galaxy 100 million light-years away would be moving away at 20 km/s * 100 = 2,000 km/s.

Suppose That Hubble's Constant Were 20 Kilometers Per Second Per