Answer
The motor pumps 55,000 liters of water in one hour.
Work Step by Step
We can convert the power of the motor to units of watts.
$P = (2.0~hp)(746~W/hp)$
$P = 1492~W$
We then find the total energy supplied by the motor in one hour.
$E = P~t$
$E = (1492~W)(3600~s)$
$E = 5.37\times 10^6~J$
The energy supplied by the motor will be equal to the change in potential energy of the water. Let $M$ be the mass of the water.
$PE = 5.37\times 10^6~J$
$Mgh = 5.37\times 10^6~J$
$M = \frac{5.37\times 10^6~J}{gh}$
$M = \frac{5.37\times 10^6~J}{(9.80~m/s^2)(10~m)}$
$M = 55,000~kg$
Since the density of water is 1.0 kg/liter, the motor pumps 55,000 liters of water in one hour.
