Question

Water falls from a height of $60m$ at the rate of $15kg/s$ to operate to turbine. The losses due to frictional forces are $10$% of energy. How much power is generated by the turbine? ($g=10m/s^2$)

• A. $12.3kW$
• B. $7.0kW$
• C. $8.1kW$
• D. $10.2kW$

Answer 1

The correct option is C $8.1kW$

Change in potential energy of the water per second is,

$\Delta P=\frac{mgh}{t}$

$\Delta P=15\times 10\times 60$

$\Delta P=9000J$

Power generated by turbine is equivalent to 90% of energy is used to turn the turbine,

$P=90$

$P=8100Watt$

$P=8.1kW$