Pascal's Principle

Pressure is transmitted undiminished in an enclosed static fluid.

Hydraulic Press

A multiplication of force can be achieved by the application of fluid pressure according to Pascal's principle, which for the two pistons implies This allows the lifting of a heavy load with a small force, as in an auto hydraulic lift, but of course there can be no multiplication of work, so in an ideal case with no frictional loss: Calculation

Hydraulic Press Calculation

Example of hydraulic press action. For piston radii: = cm =in = cm =in the cylinder areas are = m^2 = m^2 and the force multiplication is = For an input force = N = lb, Pascal's principle gaurantees that = kPa = lb/in^2.

Applying this pressure to the output cylinder yields the lifting force:
= N = lb,
A price must be paid for an increased lifting force, since conservation of energy must be satisfied. For an ideal hydraulic press, the work must satisfy , so that to lift the load a distance of
= m = ft, the input piston must be moved a distance
= m = ft,

Automobile Hydraulic Lift

Force multiplied by hydraulic press, based on Pascal's principle. The fluid in the small cylinder must be moved much further than the distance the car is lifted.