Calculate the power required to pump 5 m³ of water per minute to a reservoir 30 m above the water level if the efficiency is 80%.

• Volume of water, $V = 5 \text{ m}^3$
• Time, $t = 1 \text{ minute} = 60 \text{ seconds}$
• Height, $h = 30 \text{ m}$
• Efficiency, $\eta = 80\% = 0.80$
• Density of water, $\rho = 1000 \text{ kg/m}^3$ (standard value)
• Acceleration due to gravity, $g = 9.81 \text{ m/s}^2$ (standard value)

The mass ($m$) of water can be found using its density ($\rho$) and volume ($V$):

Useful power ($P_{out}$) is the rate at which potential energy is gained by the water.

Efficiency ($\eta$) is defined as the ratio of useful power output to the total power input ($P_{in}$):

Rearranging the formula to find $P_{in}$:

The power required to pump the water is $\text{30656.25 W}$.