29-04-10: Energy of a sphere.

What is the energy needed to accumulate a sphere of a mass M and radius R (better language?)

* A very standard question...

6 Answers

why is no one even having a look at this?

3GM²/5R ?

???

341

Hari Shankar ·2010-08-18 08:34:17

\frac{3GM^2}{4R^2}?

dw=vdm=-(Gm dm)/r

Therefore,w=-GM^2/2R

Thus ,sef potential energy=GM^2/2R.

341

Hari Shankar ·2010-08-19 01:37:39

oops sorry, qwerty has the rite answer. Sagnik: how did that r change magically into R?

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