Question

Question 25
What is power? How do you differentiate kilowatt 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? ($g=10m{s}^{-2}$)

Answer 1

Power is the rate of doing work. Kilowatt is the unit of power and kilowatt hour is the unit of energy.
$h=20m$, and $mass=2000\times {10}^{3}kg=2\times {10}^{6}kg$

$Power=\frac{mgh}{t}=\frac{2\times {10}^6\times 10\times 20}{60}W$

$=\frac{4}{6}\times {10}^{7}W$
$=\frac{2}{3}\times {10}^{7}W$
$=0.667\times {10}^{7}W$
$=6.67\times {10}^{6}W$