3 Fluid Statics Pressure Boyle’s Law Pascal’s Principle Archimedes’ Principle
4 Pressure Force per unit area Pascal = N/m2 (english sys: psi)Results from the weight of the fluid above
5 Pressure Force per unit area Pascal = N/m2 (english sys: psi)Results from the weight of the fluid above
6 Pressure Force per unit area Pascal = N/m2 (english sys: psi)Results from the weight of the fluid abovepure water1 L = 1 kg = 9.80 N1 ft3 = 62.4 lbsseawater (average)1 L = 1.03 kg = N1 ft3 = 64 lbs
7 Pressure Air is 0.1% as dense as water Atmosphere 52 miles high Pressure at sea level1 atm = 14.7 psi = 1 kg/cm2 = 1x105 P1 atm = 10 m of seawater
8 Pascal’s PrinciplePressure exerted in a fluid is the same in all directions
9 Pascal’s Principle Connect a large & small syringe via a plastic tube. Depress first one plunger then the other.Which one is easier? Why?Which one moves farther (in relation to the other)? Why?Fill the system with water & repeat the experiment.Why is it very bad to have air bubbles in your car’s brake lines?
10 Pascal’s PrinciplePressure exerted on a fluid in a closed system is the same throughout the system
11 Boyle’s Law Gases Only Pressure = Volume Pressure = Volume Pressure exerted on the outside of a gas is inversely proportional to the volume of the gas, if its temperature remains constant. Pressure = Volume Pressure = VolumeP1 = V2P2 V1
12 Archimedes’ Principle Weigh a fishing weight using a spring scale.Weigh it once again, but immersed in water.What is the buoyant force on the weight?How much water is displaced by the weight?What is the weight of the water displaced?Compare buoyant force to weight of water displaced.
13 Archimedes’ Principle Any object that is immersed in a fluid, in whole or in part, will be buoyed up by a force equal to the weight of the fluid displaced.
14 Archimedes’ Principle Buoyant ForceUpward force exerted on an object by a fluid in which it is immersed
15 Archimedes’ Principle States of BuoyancyPositiveNeutralNegative
16 Archimedes’ Principle An object will sink into a fluid until it displaces an amount of the fluid equal to its own weight.
17 Archimedes’ Principle FloatObject weighs less than the fluid it displacesSinkObject weighs more than the fluid it displaces