A 2.3 kg pendulum bob hangs from a 2 meter string. It is pulled to the side, position A, so that the bob is 111 cm (h on the sketch) above the lowest position, position C. The bob is released and begins to swing. See below.

What is its potential energy after it has swung to position B, 31.0 cm below the starting point?

And, how fast is it moving at that point?