| English | Hydraulic system |
|---|---|
| Bahasa Melayu | Sistem hidraulik |
| 中文 | 液压系统 |
Definition
A system that uses Pascal's principle to multiply force by transmitting pressure through an enclosed liquid, as in a hydraulic jack.
In exam terms
A hydraulic system is a machine that uses an enclosed liquid to transmit and multiply force, working on Pascal's principle. Pressure applied at a small piston is transmitted equally and undiminished through the liquid to a large piston, where it acts over a bigger area to give a larger force.
Because the pressure is the same at both pistons, F₁ ÷ A₁ = F₂ ÷ A₂. For example, a force of 50 N on a piston of area 0.001 m² makes a pressure of 50 000 Pa; on a large piston of area 0.01 m² this gives F₂ = 50 000 Pa × 0.01 m² = 500 N. This force-multiplying idea is used in the hydraulic brake and the hydraulic jack.
Do not confuse it with Pascal's principle
Do not confuse the hydraulic system with Pascal's principle itself. Pascal's principle is the law stating that pressure on an enclosed fluid is transmitted equally in all directions; the hydraulic system is the practical machine that applies that law to multiply force.
One is the rule, the other is the device.
In Paper 2 you may be asked to explain how a hydraulic system multiplies force, where you state that pressure is equal at both pistons and the larger area gives a larger force, then support it with F₁ ÷ A₁ = F₂ ÷ A₂. A common calculation asks for the output force given the two areas and the input force.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)