If most of the mass of a galaxy is located near the center of the galaxy, then in the outer part of this galaxy the orbital speeds of stars must decrease with increasing distance from the center. This behavior would be equivalent to
A) Newton's third law.
B) Wien's law.
C) Hubble's law.
D) Kepler's third law.

Question

Quizplus · Accepted Answer

Kepler's third law describes the relationship between the distance of planets from the Sun and their orbital periods, implying that objects farther from the center of mass (like the Sun or, by analogy, the center of a galaxy) should move slower if most of the mass is concentrated at the center. This principle can be applied to the orbital speeds of stars in a galaxy, where speeds would decrease with increasing distance from the center if the mass distribution followed a similar pattern.

If Most of the Mass of a Galaxy Is Located