Consider a ball of dust mass M, Radius R stats from rest and collapses due to gravity.(adsbygoogle = window.adsbygoogle || []).push({});

Q. Find total time of collapse.

This I am currently working on I believe I can show this using conservation of momentum.

Q. Prove that it remains homogeneous

Dose anyone have any ideas on this one, I am sure I have done this before. I have tried proving it using gauss's law by setting up gauss sphere's inside and out but I am missing something.

Thanks for any help

Robert

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# Mass collapse problem

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