[Science Form 5] Hydraulic Jack

Operation of a hydraulic jack

The hydraulic jack work on a system of valves,pistons and reservoirs. When the small piston is lifted, liquid rushes in from the reservoir through the open valve P. In the meantime, valve Q is closed. The cylinder connected to the small piston is filled with fluid.

When the small piston is pressed downwards, the pressure produced is transferred onto the liquid to the big piston. At the same time, valve P closes and valve Q opens.

A huge force is created depending on the area of the big piston. The, the lift on the big piston exerted is locked in position.

With another lift from the small piston, the big piston is lifted higher and higher until the desired height is reached. The tyre can then be changed. Work on the undercarriage of the car can also be carried out.