(a) What is the difference between gravitational potential energy and elastic potential energy? Give one example of a body having gravitational potential energy and another having elastic potential energy.
(b) If 784 J of work was done in lifting a 20 kg mass, calculate the height through which it was lifted.
(a) Gravitational potential energy is the potential energy due to the position of the body above the ground. While elastic potential energy is the potential energy due to change in the shape and size of the body. Storing of water in the overhead tank is an example of gravitational potential energy while stretching of a rubber band is an example of elastic potential energy.
(b) Work done, W = 784J
Mass, m = 20 kg
g = 9.8 m/s2
W = mgh
h = \(\frac{W}{mg}\)
h = 4m