A 56kg student runs at 5m/s, grabs a hanging rope and swings out over a lake. He releases the rope when his velocity is zero. The length of the rope is 10m, what is the angle when he releases the rope? (The person swings from the centre to the right).

Answer 1

KE at start = (1/2) m v^2

= PE at end = m g h = m g(10)(1-cos Theta)

Answer 2

Just before he releases it it is doing nothing, zero.