If the distance of a galaxy is 100 Mpc,what is its recessional velocity if the Hubble constant is 72 km/s/Mpc?
A) 0.72 km/s
B) 1.40 km/s
C) 1,000 km/s
D) 7,200 km/s

Question

If the distance of a galaxy is 100 Mpc,what is its recessional velocity if the Hubble constant is 72 km/s/Mpc?
A) 0.72 km/s
B) 1.40 km/s
C) 1,000 km/s
D) 7,200 km/s

Quizplus · Accepted Answer

We can use Hubble's Law, v= H0 x d, where v is the recessional velocity, H0 is the Hubble constant, and d is the distance of the galaxy in Mpc. 
Substituting the values given, 
v = 72 km/s/Mpc x 100 Mpc = 7,200 km/s 
Therefore, the correct answer is D.

If the Distance of a Galaxy Is 100 Mpc,what Is