You observe the following three galaxies and measure their respective recession velocities: A, 2,100 km/s; B, 4,400 km/s; and C, 3,050 km/s.Which of the following must be true about these galaxies?
A) A is smaller than B.
B) A has more star formation than C.
C) B has more stars than C.
D) B is farther away from us than A.
E) They are all members of the Local Group.

Question

Quizplus · Accepted Answer

According to Hubble's Law, a galaxy's recession velocity is proportional to its distance from us. Therefore, a higher recession velocity indicates that galaxy B is farther away from us than galaxy A.

You Observe the Following Three Galaxies and Measure Their Respective