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pooface

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## Homework Statement

A waterfall is 85ft high, and 3000 cubic ft/sec flow over it driving a water wheel connected to an electric generator. If the overall efficiency is 22%, how many kilowatts does the generator develop?

## Homework Equations

density of water =1000kg/cubic meter

P.E. = mgh

weight=density*g*volume

## The Attempt at a Solution

Firstly convert to SI units.

85ft = 25.91m

3000 cubicft/sec = 914.4 cubic meter/sec

weight of the water being applied = (1000)(9.81)(914.4)

= 8.97 MN

P.E.=(8.97 MN)(25.91m)

=232.42 MJ

power in = 232.42 MJ /1sec = 232.42 megawatts

eff =0.22

0.22 = POUT/232.42 MW

Are my steps correct?