JEE MAINS

Pascal's Laws relates to pressures in fluids - liquid or gaseous state:*.if the weight of a fluid is neglected the pressure throughout an enclosed volume will be the same*.the static pressure in a fluid acts equally inall directions*.the static pressure acts at right angles to any surface in contact with the fluidExample - Pressure in an Hydraulic CylinderThe pressure of2000 Pain an hydraulic cylinder acts equally on all surfaces. The forceon a piston with area0.1 m2can be calculated asF = p A (1)whereF = force (N)p = pressure (Pa, N/m2)A = area (m2)or with valuesF = (2000 Pa) (0.1 m2)=200(N)Example - Force in a Hydraulic JackThe pressure acting on both pistons in a hydraulic jack is equal.The force equation for the small cylinder:Fs= p As (2)whereFs= force acting on the piston in the smallcylinder (N)As= area of small cylinderp = pressure in small and large cylinderThe force equation for the large cylinder:Fl= p Al (2b)whereFl= force acting on the piston in the large cylinder (N)Al= area of large cylinderp = pressure in small and large cylinder(2) and (2b) can be combined toFs/ As= Fl/ Al (2c)orFs= FlAs/ Al (2d)The equation indicates that the effort force required in the small cylinder to lift a load on the large cylinder depends on the area ratio between the small and the large cylinder - the effort force can be reduced by reducing the small cylinder area compared to the large cylinder area.