What is the Potential Power Output of a Waterfall?

[pinnacleprouk]

I don't think I have done it right!

Thanks In Advance!

Homework Statement

Water flows over a 60-m high waterfall at a rate of 2000kg every 5 seconds.
What is the potential power output of the water fall?

Homework Equations

KE = 1/2 mV*2

V = Displacement/time

P = E/t

The Attempt at a Solution

To find out velocity using V = x/t got 12m/s

Using KE = 1/2 mV*2 1/2 x 2000 x 12*2 = 144000J

Using P = E/t 144000/5 = 28800W

 

[pinnacleprouk]

No worries I have figured it out

400 kg/s falls 60 m
Energy = mgh = 400 x 9.81 x 60 = 235440 J/s = 235440 W = Power

Thanks

 

[paul232]

Do you understand your mistake in your first attempt? The time you are given is not the time the motion of 2000kg lasts.