A pump discharges 50 ton of water per hour at the height of 8 m. The overall efficiency of the pumping system being 69%. Calculate the energy consumed by the pump in 2 hours, expressed in MJ.

$\text{Energy} = \left( 50 ~ \text{ton} \times 1000 ~ \dfrac{\text{kg}}{\text{ton}} \times 9.81 ~ \text{m/sec}^2 \right) 8 ~ \text{m}$

$\text{Energy} = 3,924,000 ~ \text{N}\cdot\text{m or J}$

$\text{Energy} = 3.924 ~ \text{MJ}$

$\text{Energy} = 7.848 ~ \text{MJ}$

$0.69 = \dfrac{7.848}{\text{Input}}$

$\text{Input} = 11.3739 ~ \text{MJ}$