Power from a 30m waterfall and lighting bulbs from it

[cowgiljl]

a waterfall is 30 m high and 10000 kg of water flow over it every second
A) calculate the potential energy
PE = mgh
got 2.94E6 joules

B) calculate the power delevered by the water of all the potential energy is converted to work

F = mA
F= 10000 * 9.80
f = 98000

w = Fm
w 98000 * 10000
w = 980 MJ mega joules

C)If all the power were converted to electricity, how many 100watt light bulbs could be lit

not even sure on how to approach this
[?]

 

[himanshu121]

B is WRONG Look at the physicsl dimensions when u multiply force by mass is it Energy

 

[himanshu121]

Look the energy mgh which u calulated is per second
which is power itself

with this energy u can lit mgh/100 bulbs

hope u will get now