Question

A star with a mass of 3.72 x 1030 kilograms and a radius of 8.67 x 108 meters rotates on its axis once every 32 days. A star is a solid sphere, which has a k value of 2/5. a. What is the angular speed of the star? Include units in your answer.b. What is the moment of inertia of the star? Include units in your answer.c. What is the angular momentum of the star? Include units in your answer.d. After running out of fusible matter, the star collapses under its own gravity to form a pulsar with a radius of 26.7 kilometers. What is the moment of inertia of the pulsar? Include units in your answer.e. What is the angular speed of the pulsar? Include units in your answer.f. What is the period of rotation of the pulsar? Include units in your answer.All answers must be in 3 significant digits.

Answer 1

Given data:

* The radius of the star is,

`R=8.67*10^8\text{ m}`

* The time it takes to complete one rotation is,

`T=32\text{ days}`

Solution:

(a). The angular frequency of the star is,

`\begin{gathered} \omega=(2\pi)/(T) \\ \omega=(2\pi)/(32) \\ \omega=0.196\text{ rad/day} \end{gathered}`

Thus, the angular speed (angular frequency) of the star is 0.196 radian per day.