Question

25 marks (allow 30 minutes) QUESTION 1 A 3-m diameter roller gate retains water on both sides of a dam crest as shown below. Axes (x,y) are given in the diagram to indicate the convention for positive values. The origin of your coordinate system (O) is at the base of the roller gate where it contacts the dam. Indicate direction of Forces either with an arrow, writing the direction (ie. Right/left or up/down) or +/- sign indicating what way is positive based on the axes definition given. Give angles relative to the x-axis (0 degrees, measured positive counter-clockwise). Draw the angle direction for clarity. FIGURE IS NOT TO SCALE Gate 3m 3.5m 1m Dam In your exam booklet calculate the following: a) The horizontal force(s) (direction and magnitude) acting on the gate per unit width and draw the pressure distribution diagram(s) [6 marks] b) The vertical force(s) acting on the gate per unit width (Include direction and magnitude). [6 marks] c) If the gate is 5 m long (into the page), calculate the magnitude, direction and angle of the resultant hydrostatic force acting on the gate. [7 marks] d) The net horizontal force acting on the dam per unit width. Include sketches of the pressure distributions considered. [6 marks]

a) The horizontal force(s) (direction and magnitude) acting on the gate per unit width and draw the pressure distribution diagram(s) [6 marks] b) The vertical force(s) acting on the gate per unit width (Include direction and magnitude). [6 marks] c) If the gate is 5 m long (into the page), calculate the magnitude, direction and angle of the resultant hydrostatic force acting on the gate. [7 marks] d) The net horizontal force acting on the dam per unit width. Include sketches of the pressure distributions considered. [6 marks]

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