Power question.

[Unknown_20]

Water flows over a section of Niagara Falls at
a rate of 1.38 x 10^6 kg/s and falls 32 m.
The acceleration of gravity is 9.8 m/s2 .
How many 80 W bulbs can be lit with this
power?

[Deeviant]

Water flows over a section of Niagara Falls at
a rate of 1.38 x 10^6 kg/s and falls 32 m.
The acceleration of gravity is 9.8 m/s2 .
How many 80 W bulbs can be lit with this
power?

Force = Mass*Acceleration, which in this case will be in newtons.
P = Force*distance / time, note that force*distance is also called "work" and the units of work are "Joules". A watt is Joules over time, which is exactely what this equation comes up with.

That should be all you need to know.

[Unknown_20]

thanks for the help.

[aekanshchumber]

If i am not mistaken, here we have to use Newton's second law in real form that's
f=d/dt(m*v)
here velocity is not the variable but the mass (check kg/s)
work done = f*d/time

you can do the rest.