Tired slaves

Classical Mechanics Level 3

A well fed laborer can sustain a mechanical power output of roughly 75 Watts. How many person-hours are required to generate the total amount of work needed to raise the pyramid blocks off the ground into the shape of the great pyramid?

Image credit: Wikipedia Mike Knell

The answer is 9360370.37.

1 solution

Gaurav Sharma
Jun 15, 2014

Since Watts is $J/s$ . A person does roughly $75 \times 60\times 60$ joules of work per hour.

Total work done was $W=$ $2.5272975\times 10^{12}$ from previous example.

So the total number of person hours will be given by $Total Work Done /$ $Person's Work Per Hour$

which is $2.5272975\times 10^{12}/$ $(75 \times 60\times 60)$ , that is $9360361.11111$

or more precisely $\boxed {9360361}$ person hours.

Very good......!

Siva Prasad - 6 years, 9 months ago

What do you mean "from previous example"? I haven't seen that. I got this problem as the first in a series of five. My rough estimate from basic assumptions was 9000000, and this was considered incorrect. However, it is close enough to be considered correct.

Tom Verhoeff - 4 years, 2 months ago

Thanks, I've removed this problem from the challenge quiz. It was meant to be part of a set.

Calvin Lin Staff - 4 years, 2 months ago

Tired slaves

Image credit: Wikipedia Mike Knell

The answer is 9360370.37.

1 solution

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