Question

A dam is situated 550 metres above the sea level and supplies water to power house which is at the the hieght of 50 metres above sea level.2000 kg of water passes through the turbines per second.The maximum electrical power output of the power house if the whole system were 80 percent efficient is

Answer 1

ANSWER:

The maximum power should be 9084 voltage required for the power supply.

EXPLANATION:

Power = rate of transfer of energy = rate of loss of PE in this case ..  

PE = mgh  

PE rate of loss = (mg∆h) / t = (m/t)g∆h .. .. (m/t) = mass of water per sec (kg/s)  

= 2000kg/s x 9.80 x (550-50)m = 9.80^6 J/s (W) .. at 100% efficiency  

At 80% efficiency, power output = 0.80 x 9.80^6W .. .. ►P = 7.84^6 W