Inside a hydroelectric power station, a turbine lies at a vertical depth of $30\,\text{m}$ below the surface of a large lake. Water flows through the turbine at a rate of $340\,\text{m}^3\,\text{per minute}$. The combined efficiency of the turbine and generator system is $90\%$. The density of water is $1000\,\text{kg m}^{-3}$. Calculate the useful power output of the power station?
- A$0.15\,\text{MW}$
- B$1.5\,\text{MW}$
- C$1.7\,\text{MW}$
- D$90\,\text{MW}$