New Angular Velocity of Star with Diameter Shrink to 0.17 Times

[Naldo6]

The mass of a star is 1.1e31 kg and its angular velocity is 1.40×10-7 rad/s. Find its new angular velocity if the diameter suddenly shrinks to 0.17 times its present size. Assume a uniform mass distribution before and after. [Icm for a solid sphere of uniform density is 2/5 mr^2].


Can anyone helps me please?... i don't know hoyw to begin this exercise...

 

[alphysicist]

Hi Naldo6,

The mass of a star is 1.1e31 kg and its angular velocity is 1.40×10-7 rad/s. Find its new angular velocity if the diameter suddenly shrinks to 0.17 times its present size. Assume a uniform mass distribution before and after. [Icm for a solid sphere of uniform density is 2/5 mr^2].


Can anyone helps me please?... i don't know hoyw to begin this exercise...

What quantity would be conserved in this process?

 

[Naldo6]

can u solve me this problem?...

 

[alphysicist]

can u solve me this problem?...

I'm sorry Naldo, but forum rules here prohibit doing someone else's homework for them. If I were to just solve the problem for you the multitude of homework helpers and mentors would unite and rise against me and crush me like a worm.

So instead of that, think of what quantity would be conserved here. There should only be a few conserved quantities that you have studied: energy, momentum, etc. What other conservation equation have you studied, that applies here? Once you have determined that, you can use that to write an equation that will help you solve the problem.