(b) Fig.Q1 shows a rectangular sluice gate AB, 3 m wide and 4.5 m long hinged at A. It is kept closed by a weight fixed to the gate. The total weight of the gate and the weight fixed to the gate is 515 kN. The centre of gravity of weight and gate is at G. Find the height of water h which will cause the gate to open. Water surface V A Hinge T W P 10.9 m Fig.Q1. 4.5 m C Gate 45% (12 marks)