maths
posted by Anonymous .
A rectangular reservoir is 120m long,and 75cm wide .at what speed per hour must water flow into it through a square pipe of 20cm wide so that the water rises by2.4m in 18hrs.

to rise by 2.4m in 18 hours, the volume must increase by
120*.75*2.4 = 216 m^3/hr
the square pipe has crosssection area of .2^2 = .04 m^2
216 m^3/hr / .04m^2 = 5400 m/hr