What is power ? How do you differentiate killowatt from kilowatt hour ? The Jog Falls in Karnataka state are nearly 20 m high. 2000 tonnes of water falls from it in a minute. Calculate the equivalent power if all this energy can be utilized ? `(g = 10 m//s^2)`

Explanation

(i) Power is defined as the rate of doing work or the rate of tranfer of energy. The unit of power is watt or kilowatt. `[1KW=1000W]`
(ii) Kilowatt is the unit of power while kilowatt hour is bigger unit of energy
`1kWh=1000xx3600rArr1"kilowatt hour"=3.6xx10^(6)J`
(iii) Given, mass of of water =2000 tonnes [:' 1 tonne=1000kg]
`:."Mass of water"=2000xx1000=2xx10^(6)kg`
We know that, power `=("energy")/("time")`
`P=(mgh)/(t) " "[:'"energy"=mgh]`
`P=(2xx10^(6)xx10xx20)/(60)["given",h=20m and g=10ms^(-2)]`
This power can be utilised.