Water is pumped along a hose-pipe at a flow rate of $90\ \text{kg}\ \text{per minute}$. It leaves the hose-pipe horizontally at a speed of $20\ \text{m s}^{-1}$. What minimum force must a person apply to the hose-pipe to stop it from moving backwards?
- A$30\ \text{N}$
- B$270\ \text{N}$
- C$1800\ \text{N}$
- D$108\ 000\ \text{N}$