A trough is 9 meters long, 1.5 meters wide, and 5 meters deep.

A trough is 9 meters long, 1.5 meters wide, and 5 meters deep. The vertical cross-section of the trough at the top parallel to an end is shaped like an isoceles triangle (with height 5 meters, and base, on top, of length 1.5 meters). The trough is full of water (density 1000kgm3 ). Find the amount of work in joules required to empty the trough by pumping the water over the top.