Pressure and Hydraulics
Pressure: P = F / A (force per unit area). Measured in pascals (Pa) or psi. A concentrated force on a small area = high pressure.
Pascal's Principle: Pressure applied to an enclosed, incompressible fluid is transmitted equally in all directions throughout the fluid.
Hydraulic force multiplication: F₁/A₁ = F₂/A₂
Small piston (2 cm²) with 10 N applied → pressure = 5 N/cm². Large piston (20 cm²) → force = 5 × 20 = 100 N. Force multiplied 10×.
Trade-off: The small piston must move 10 cm for the large piston to move 1 cm. Conservation of energy always applies.
Applications: car jacks, hydraulic brakes, excavators, hydraulic presses.