How much work is needed to build the pyramid ?

Suppose that it took 20 years to construct the great pyramid of Khufu at Gizeh in Egypt. This pyramid is 500 feet high and has a square base with edge length 750 feet. Suppose also that the pyramid is made of rock with density 蟻 = 120 lb/cubic foot.|||v = 1/3 * l * w * h = 1/3 * 750^2 * 500 = 250 * 750 * 500 = 93,750,000 cu ft





but where is the center of mass?


suppose a pyramid was 2*2*2 = 8


then the center of mass would be 4^.33333 = 1.5874 from the top.


if the pyramid was 1*1*1 then the center of mass would be 1-.5^.3333333 =0,2063 from the bottom.





so, 500 *.2063 *93,750,000 *120 = 1,160,437,500,000 ft lbs