A small hydroelectric power station channels water away from a river. Each second, $20\,\text{kg}$ of water passes through a pipe and drops through a vertical height of $15\,\text{m}$. The efficiency of the power station is $0.60$ (60%). The gravitational field strength is $g = 10\,\text{N kg}^{-1}$. What is the power output?
- A$0.18\,\text{kW}$
- B$1.8\,\text{kW}$
- C$3.0\,\text{kW}$
- D$180\,\text{kW}$