Sharing the load

You can lift a load all by yourself, or ask 3 other friends to share the load, one on each corner.

Give us a hand up

You could use a set of pulleys to share the load.

Each section of rope leaving the load shares the weight. You hold one section. Add more sections of rope by adding more pulleys so that you have to support less of the weight.

You could use a hydraulic system to support the weight. You push down on a piston resting on one area of the hydraulic fluid: the load rests on another piston of larger area, resting on hydraulic fluid. A larger area under the load supports more of the weight: less is left for you.

sharing the distance

Egyptians built their pyramids by dragging huge stones up ramps: gaining height more gradually. Many paths and roads up hills zigzag, gaining height a little at a time. You climb a step at a time, choosing many steps up a gentle slope, rather than fewer steps up a steep slope.

Lift a load with a ramp and friends: you pull the load up a little, then hand it on to a friend. The more friends, the less each of you have to do, sharing the distance.

Get it so far, then hand it over

But choosing a longer distance results in a smaller force. Just imagine trying to cycle straight up a steep hill, rather than following the less steep zig-zags.

sharing load or distance

In all three cases you'll notice a bit of a trade-off. You can choose to share the weight, but then you have to pull or push for a greater distance. Or the other way around.

This is clear for the lever.

One way or the other, change costs. You can choose how to pay, but can't choose not to pay.