The sprinkler is made to rotate at the constant angular velocity ω and distributes water...

The sprinkler is made to rotate at the constant angular velocity ω and distributes water at the volume rate Q. Each of the four nozzles has an exit area A. Write an expression for the torque M on the shaft of the sprinkler necessary to maintain the given motion. For a given pressure and, thus, flow rate Q, at what speed ω₀ will the sprinkler operate with no applied torque? Let ρ be the density of the water.