A horde of people

Given the total number of person hours from the last problem, and assuming that one can work a slave for 12 hours a day continuously, 365 days a year, how many people would it take to generate enough work to simply raise the blocks of the pyramid off the ground in 20 years?

Note: the answer is around 100. In other words, roughly 100 people, doing nothing for 12 hours a day but lifting stuff, would barely generate enough mechanical energy simply to get the pyramid blocks in place! When you think about the addition of friction, carving the blocks, feeding people, moving blocks along the ground, etc. you rapidly understand why building the great pyramid required the effort of tens of thousands of people over twenty years.

Image credit: Canadian Museum Of History