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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?