Suppose a galaxy is 400 million pc from Earth. What is the recessional velocity of this galaxy? Assume Hubble's constant to be 73.5 km/s per Mpc.

Question

Quizplus · Accepted Answer

The recessional velocity of a galaxy can be calculated using Hubble's Law, which is $v = H_0 \times d$, where $v$ is the recessional velocity, $H_0$ is Hubble's constant (73.5 km/s per Mpc), and $d$ is the distance to the galaxy (400 million pc or 400 Mpc). Thus, $v = 73.5 \times 400 = 29,400$ km/s.

Suppose a Galaxy Is 400 Million Pc from Earth