Physics energy of pendulum

Question

A 16.9 kg monkey is swinging on a5.32 m long vine. At the bottom ofits swing, it is moving 11.3 m/s. Towhat height does it swing?(Unit = m/s(

Answer 1

To solve the problem, you need to use the law of conservation of mechanical energy. On the bottom the monkey has only kinetic energy K = 1/2 mv². Then it moves up and all kinetic energy will be converted to potential energy of the pendulum U = mgh, here h - height against zero's level of energy. In this case it is the line, that is parallel to the surface and going through bottom point. You can write

mgh = 1/2 mv²

^{From this equation you will get expression for height}

h = v² /2g