Water falls from a \(40 \mathrm{~m}\) high dam at the rate of \(9 \times 10^{4} \mathrm{~kg}\) per hour. Fifty percent o…

Water falls from a \(40 \mathrm{~m}\) high dam at the rate of \(9 \times 10^{4} \mathrm{~kg}\) per hour. Fifty percent of gravitational potential energy can be converted into electrical energy. Using this hydro electric energy number of \(100 \mathrm{~W}\) lamps, that can be lit, is: (Take \(\mathrm{g}=10 \mathrm{~ms}^{-2}\) )