My name is Alexander FufaeV and here I write about:

How Does a Hydraulic Press Work?

The hydraulic press is a container with two cylinders filled with an incompressible fluid (e.g. oil). The diameter of one cylinder is much larger than the diameter of the other cylinder.

Sketch of a hydraulic press.

If you now exert a force $ F_1 $ on the contact surface $ A_1 $ of the cylinder with the smaller diameter, you generate pressure ($ \mathit{\Pi} ~=~ F_1 / A_1 $) in the container. Since the fluid is incompressible, the generated pressure acts at all points of the container – including on the much larger contact surface $ A_2 $ of the other cylinder.

If, for example, a car is standing on the support surface $ A_2 $, it will be lifted with ease because the force $ F_2 $ on the second support surface is much greater than $ F_1 $, because in this case the following relationship applies:

$$ \begin{align} \frac{F_1}{A_1} ~=~ \frac{F_2}{A_2} \end{align} $$

Rearranging with respect to the force $ F_2 $ results:

$$ \begin{align} F_2 ~=~ \frac{A_2}{A_1} \, F_1 \end{align} $$

As you can see, the force on the second bearing surface is greater by the factor $ \frac{A_2}{A_1} $!