# Physics

posted by
**Jim**
.

I need help solving the problem below. Please respond.

At the local swimming hole, a favorite trick is to run horizontally off a cliff that is 8.9 m above the water. One diver runs off the edge of the cliff, tucks into a "ball," and rotates on the way down with an average angular speed of 1.4 rev/s. Ignore air resistance and determine the number of revolutions she makes while on the way down.

Multiply the time T required to fall 8.9 m (in seconds) by the rotation rate in rev/s.

Derive the time T from

(1/2) g T^2 = 8.9 m