The Great Pyramid of Giza is 485 ft high and has a square base of side 755.5ft. Find the work needed to build the pyramid if the density of the stone is estimated at 125 lb/ft^3.

Note: the solution manual says the answer should be 1.399 x10^12 ft-lb, I just don't know how to get there?

First find the volume of the pyramid using

[LaTeX Error: Can't write to directory].

From this find the mass m of the pyramid using the density of stone given.

Look up how high the centre of mass of the pyramid is above the base.

Let this be h.

Treat the pyramid as a point particle of mass m with its position represented by its centre of mass.

The work done would be equal to the increase in P.E. = m.g.h


I am sure there would be more rigorous solutions using calculus, but i dont think that is what is expected here.