Question

If a galaxy A is four times more distant than galaxy B, then according to Hubble's law, galaxy A will recede:

a. 16 times faster
b. 4 times faster.
c. 2 times faster.
d. at the same speed
e. 2 times slower
f. 4 times slower
g. can not say unless the Hubble constant is known

Answer 1

According to Hubble's law, galaxy A, being four times more distant than galaxy B, will recede 4 times faster.

Step-by-step explanation:

If galaxy A is four times more distant than galaxy B, then according to Hubble's law, the velocity at which galaxy A is receding would be four times greater than that of galaxy B. Hubble's law is stated as v = H × d, where v is the recession velocity, H is the Hubble constant, and d is the distance to the galaxy. Because the recession velocity is directly proportional to distance, if one galaxy is four times farther away than another, it will be receding four times faster. Therefore, the correct answer to this question is (b) 4 times faster.