Circular motion in a vertical plane

[nokia8650]

http://img27.imageshack.us/img27/1073/98488419.th.jpg

I was unable to prove the equality shown in the question. Can someone please explain how to do so?

Thank you.

 

[Dick]

What did you try? Equate the kinetic energy and the gravitational potential energy. This is probably more of a physics question than a calculus question.

 

[nokia8650]

Thanks for the reply, I have got it now.

 

[Dick]

Not until you show what you've done so far. Your problems can't be that serious. It's a pretty easy question.