a trough is 8 meters long, 2.5 meters wide, & 3 meters deep. The vertical cross-section of the trough parallel to an end is shaped like an isosceles triangle (with height 3 meters, and base, on top, of length 2.5 meters). The trough is full of water (density 1000 kg÷ m3). Find the amount of work in joules required to empty the trough by pumping the water over the top.) (Note: Use g=9.8 m÷a2 as the acceleration due to gravity.)

Answer 1

the weight of water is 1/2 * 3 * 2.5 * 8 * 1000 * 9.8 = 29400 N
The center of mass of the water is at a depth of 1 meter
so, the work required is 29400N * 1m = 29400 J