Q1 A 2-m wide rectangular gate shown below in Figure Q1 is pinned at P and is connected to a restraining spring that keeps the gate closed until the hydrostatic force is sufficient to open the gate. The spring has a spring rate of N K = 100,000- spring m and the water depth to the bottom of the gate is 4m. Air Pin Water 4m Gate P 1m 45 w Spring Figure Q1: Gate with restraining spring If the gate is to open when the depth of the water is 4m, find the following; (i) The depth to the geometric centre, y (ii) The Resultant Force, R (iii) The depth, D at which the Resultant Force acts (iv) The spring force to keep the gate closed The spring extension at this spring force Note: D= sin | y KGG +y and the Spring Force is given by Fs, = K spring spring .x. (10 Marks) (20 Marks) (30 Marks) (30 Marks) (10 marks)