Chapter 7, Problem 16PE

A hydroelectric power facility (see Figure 7.38) converts the gravitational potential energy of water behind a dam to electric energy. (a) What is the gravitational potential energy relative to the generators of a lake of volume 50.0 km³ $\left(\text{mass}=5.00\times {10}^{13}\text{Kg}\right)$, given that the lake has an average height of 40.0 m above the generators? (b) Compare this with the energy stored in a 9-megaton fusion bomb.

Figure 7.38 Hydroelectric facility (credit: Denis Belevich, Wikimedia Commons)