The pumped-storage hydroelectricity pumps water from the lower elevation reservoir to a higher elevation to store electricity. Suppose that the water is pumped out
from the upper elevation which is h meters above the top to the lower reservoir. The
lower reservoir has the shape of half ball with radius r meters. The lower reservoir is
full at the beginning. How much work should be done given the density of water is ρ
kg/m3? You do not need to replace the acceleration g as 9.8m/sec2. Just leave g in
the expression.