- #1

samjohnny

- 84

- 1

## Homework Statement

Question: A mass m attached to a light string is spinning in a vertical circle, keeping its total energy constant. Find the difference in the magnitude of the tension between the top most and bottom most points.

## The Attempt at a Solution

So for this one I've worked out that the tension at the top=(mVt^2/r)-mg and at the bottom=(mVb^2/r)+mg where r=radius of circle, Vb is the velocity at bottom and Vt is velocity at top. And I've also worked out that, since the total energy is conserved, Energy at top [KE+PE]=Energy at bottom [KE+PE] ==> [(mVt^2)/2]+mg2r=(mVb^2)/2.

But I don't where to go from there and work out the two tensions. Any suggestions?

Thanks