Question

1. Determine the energy of a swinging pendulum bob at its highest position, at the middle position, and at its lowest position which will be considered the reference level. The length of the string is 1 m and the height of its highest position is 1.5 m. The mass m of the bob is 0.20 kg.

Answer 1

The highest, the lowest, and medium position of the bob are of equal energies because the total mechanical energy is conserved:

$$E_\text{tot}=mgh=mg(L-h)=0.98\text{ J}.$$