FluidsFluidsPMHSPMHS

PearsonPearson20072007

Archimedes' PrincipleArchimedes' Principle

• The buoyant force on a submerged The buoyant force on a submerged object is equal to the weight of the object is equal to the weight of the fluid displaced.fluid displaced.

What Is Pressure?

Static Fluid Pressure The pressure exerted by a static fluid depends only upon the depth of the fluid, the density of the fluid, and the acceleration of gravity.

Pascal’s PrinciplePascal’s Principle• Pressure is transmitted undiminished in Pressure is transmitted undiminished in

an enclosed static fluid.an enclosed static fluid.• Any externally applied pressure is transmitted Any externally applied pressure is transmitted

to all parts of the enclosed fluid, making to all parts of the enclosed fluid, making possible a large multiplication of force (possible a large multiplication of force (hydraulic press principlehydraulic press principle). The pressure at the ). The pressure at the bottom of the jug is equal to the externally bottom of the jug is equal to the externally applied pressure on the top of the fluid plus the applied pressure on the top of the fluid plus the static fluid pressurestatic fluid pressure from the weight of the from the weight of the liquid. liquid.

A multiplication of force can be achieved by the application of fluid pressure according to Pascal's principle, which for the two pistons impliesP1 = P2This allows the lifting of a heavy load with a small force, as in an auto hydraulic lift, but of course there can be no multiplication of work, so in an ideal case with no frictional loss:Winput = Woutput

Do Fluids Contain Energy?

Kinetic Energy By Volume

Potential Energy By Volume

Bernoulli EquationBernoulli Equation