Physics Force & Laws Of Motion Level: Misc Level

A stream of water strikes a stationary trbine blade horizontally, as the drawing illustrates. The incident water stream has a velocity of +18.0 m/s, while the exiting water stream has a velocity of -18.0 m/s.The mass of water per second that strikes the blade is 18.0 kg/s.Find the magnitude of the average force exerted on the water by the blade.