The bob (weight) at the end of a pendulum has a mass of 0.3 kilograms. The bob is pulled to position B and allowed to swing. It goes all the way to position C and swings back.

The potential energy of the bob at position B is
joules. If the maximum height of the bob is 0.45 meters when it swings back,
joules of energy was transformed to thermal energy.
Use g = 9.8 m/s2 and PE = m × g × h.