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Water descends through a vertical drop of 60 m at a mass flow rate of 15 kg/s to drive a turbine. If 10% of the available energy is lost because of friction, what power is delivered by the turbine? (Take g = 10 m/s²)

1. 8.1 kW
2. 10.2 kW
3. 12.3 kW
4. 7.0 kW

Correct answer: 8.1 kW

Solution

The power delivered by the turbine is calculated using the potential energy lost due to the height drop, adjusted for the mass flow rate and accounting for the 10% energy loss. The potential energy per second is given by the formula P = mgh, where m is the mass flow rate, g is the acceleration due to gravity, and h is the height. After calculating the total power and applying the energy loss, the result is 8.1 kW.

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