posted by Brian .
Approximately 5.5 X10^6 kg of water fall 50m over Niagara Falls each second.
a) What is the decrease in the gravitational potential energy of the water-Earth system each second?
b) If all this energy could be converted to electrical energy (can’t happen) at what rate would electrical energy be supplied? (the mass of 1 m^3 of water is 1000kg)
c) If the electrical energy were sold at 1 cent/kW *h what would be the yearly cost?
a)would I use 1/2mv^2=mgh? But the thing is velocity isn't given.
For b) and c) confuses me could you please guide me into the right direction?