A turbine at a hydroelectric power station is situated 30 m below the level of the surface of a large
lake. The water passes through the turbine at a rate of 340 m3
per minute.

The overall efficiency of the turbine and generator system is 90%.

What is the output power of the power station? (The density of water is 1000 kg m–3.)
A 0.15 MW B 1.5 MW C 1.7 MW D 90 MW

Question

A turbine at a hydroelectric power station is situated 30 m below the level of the surface of a large 
lake. The water passes through the turbine at a rate of 340 m3
 per minute. 
 
The overall efficiency of the turbine and generator system is 90%. 
 
What is the output power of the power station? (The density of water is 1000 kg m–3.) 
A 0.15 MW B 1.5 MW C 1.7 MW D 90 MW

anonymous · Answer

They have given volume/time and density= so u can find the mass/time
m/t = v/t* density
m/t = 340/60 * 1000
then u can find change in pE/time = power input
m/t * g * h = 1.67 *  10^6

the use the efficiency equation answer would be B i guess