• id: JME-09-N03
• title: Pascal's Law — Hydraulic Press and Lift
• tags: pascal, hydraulic, mechanical-advantage

Pascal's Law: A pressure change at any point in a confined incompressible fluid is transmitted undiminished to all points in the fluid. Application in hydraulic press: $F_1/A_1 = F_2/A_2$, giving mechanical advantage $= A_2/A_1$. Energy is conserved: $F_1 d_1 = F_2 d_2$, where $d$ is piston displacement. The large piston moves a shorter distance. Applications include hydraulic brakes, car lifts, and hydraulic jacks. The key assumption is that the fluid is incompressible — for gases, compression would absorb energy and reduce force transmission.