For any prism-shaped geometry, the volume
(V) is assumed by the product of cross-sectional area (A) and height (h).
V = Ah
Distinguishing with respect to time gives the
relationship between the rates.
dV/dt = A*dh/dt
in the meantime the area is not altering
dV/dt = π*(1 ft)^2*(-0.5 ft/min)
dV/dt = -π/2 ft^3/min ≈ -1.571 ft^3/min
Water is draining from the tank at the rate of π/2
ft^3/min.
