Calculate the annual potential energy contained in the water that is held back by the dam. Assume an average height of the water, h of 100.0 m. Express the answer in GJ (at least three significant figures).

Question

Greta Cox

Physics

13 October, 02:16

Calculate the annual potential energy contained in the water that is held back by the dam. Assume an average height of the water, h of 100.0 m. Express the answer in GJ (at least three significant figures).

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Answers (1)

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Bruce Blackburn · Answer 1

The potential energy can be given as

E = mgh. m is mass, g = acceleration due to gravity = 9.8m/s, h is the heigh, given as 100.0m

E = m x 9.8 x 100 = (980m) J

E = (980m) / 10^9GJ = (0.000000980m) GJ to 3 significant figures

Explanation:

Hydroelectric dams exploit storage of gravitational potential energy. A mass, m, raised a height, h against gravity, g = 9.8 m/s², is given a potential energy E = mgh. The result will be in Joules if the input is expressed in meters, kilograms, and seconds (MKS, or SI units).