A spinning star begins to collapse under its own gravitational pull. Which one of the following occurs as the star becomes smaller?
A)The star's angular velocity decreases.
B)The star's angular momentum remains constant.
C)The star's angular momentum increases.
D)The star's angular velocity remains constant.
E)Both the star's angular momentum and its angular velocity remain constant.

Question

Quizplus · Accepted Answer

Angular momentum is a conserved quantity, meaning it remains constant unless acted upon by an external torque. As the spinning star collapses, its radius decreases, which causes its angular velocity to increase in order to conserve its angular momentum. Therefore, (A), (C), and (D) can be eliminated. Since angular momentum is conserved, (E) can also be eliminated. Therefore, the correct answer is (B) as the star's angular momentum remains constant during its collapse.

A Spinning Star Begins to Collapse Under Its Own Gravitational