Question

Date line: 2467 BC. The Pharaoh orders you to build the Great Pyramid of Giza 140 m high. You use a 12.5° ramp to haul stone blocks to the top of the pyramid. A group of workers pulls on a rope attached to a block. Each block weighs 145000 N. Your average individual worker has a mass of 78.5 kg and can pull with a force of 1350 N. The coefficient of friction is 0.100 between the ramp and a block.

1. Draw a diagram of the ramp showing the block, the rope and the group of workers. On the diagram draw and label the force vectors. Include convenient coordinate axes.

2. Estimate the minimum number of workers you need to pull a stone up the ramp.

3. What assumptions did you need to make?

4. The Pharaoh decides to cut your construction budget and you only have 75% of your work force. How will you do the job?

Answer 1