A horizontal stream of water with a rectangular cross-section of height 0.5 m0.5\text{ m}0.5 m and width 1.6 m1.6\text{ m}1.6 m strikes a vertical deflection plate in a hydroelectric channel.
The water flows at a speed of 18 m s−118\text{ m s}^{-1}18 m s−1 and strikes the plate for 2.5 s2.5\text{ s}2.5 s. The density of water is 1000 kg m−31000\text{ kg m}^{-3}1000 kg m−3.
Show that the mass of water which strikes the plate in this time is 36 000 kg36\,000\text{ kg}36000 kg.
Upon striking the plate, all the water is deflected at 90∘90^\circ90∘ to its original direction, parallel to the surface of the plate. Calculate the magnitude of the force FFF exerted by the water stream on the plate.
8 exam-style questions on OCR A A Level Physics Newton's laws of motion and momentum, covering Newton's laws of motion and Collisions. Each one has a worked solution and a mark scheme showing where the marks go.