In a hydroelectric power station, how much potential energy is lost by 100tonnes of water flowing down through the pipes, falling a vertical distance of 200metres? [1tonne=1000kg.]

196000000 J

Explanation:

Potential Energy: This can be defined as the energy of a body due to its position in the gravitational field.

From the question,

P. E = mgh ... Equation 1

Where P. E = potential Energy, m = mass of the water, h = height, g = acceleration due to gravity.

Given: m = 100 tonnes = (100*1000) = 100000 kg, h = 200 m

Constant: g = 9.8 m/s²

Substitute into equation 1

P. E = 100000 (200) (9.8)

P. E = 196000000 J.

Note: When a object falls through a height he losses its potential energy.

Hence the potential energy lost = 196000000 J = 196 MJ.