Let V = volume of water at time t
h = depth of water at time t
Given: dV/dt = 1 L/min = 1000 cm3/min
Find: dh/dt
Solution: The volume of water at time t is
V = (area of base)(height)
V = 100h
Differentiate with respect to t to get dV/dt = 100(dh/dt)
So, dh/dt = (1/100)(dV/dt)
= (1/100)(1000) = 10 cm/min