A hydraulic lift consists of a platform that is supported by a cylindrical piston, which resides in a tube connected to a reservoir of hydraulic fluid. The piston and platform have a mass of 300 kg. The input force is generated at a smaller piston connected to the same reservoir. If the radius of the smaller piston is 2 cm, what must be the radius of the larger piston so that a moderate force of 100 N will lift a 1,700 kg car?

2 answers

A 1700 kg car weighs M g = 16,660 Newtons. The piston and platform add 2940 N. That makes 19600 N on the heavy end.

The area ratio of the pistons must be 19,600/10 = 1960

The square root of that number is the ratio of radii.
where did the 10 come from?