Presentation on theme: "VII. Forces in Fluids (Ch. 8.5)"— Presentation transcript:
1 VII. Forces in Fluids (Ch. 8.5) Ch. 3 & 4 Motion & ForcesVII. Forces in Fluids (Ch. 8.5)Archimedes’ PrinciplePascal’s PrincipleBernoulli’s Principle
2 A. Archimedes’ Principle Fluidmatter that flowsliquids and gasesBuoyancythe ability of a fluid to exert an upward force on an object immersed in it
3 A. Archimedes’ Principle Bouyant Forceupward force exerted by a fluid on an immersed objectbouyant force > weightballoon risesbouyant force < weightballoon sinksbouyant force = weightballoon floats
4 A. Archimedes’ Principle the bouyant force on an object in a fluid is equal to the weight of fluid displaced by the objectVery little water needs to be displaced in order to cancel weight ball floats on surface.More water needs to be displaced in order to cancel weight ball floats lower in the water.Not enough water is displaced in order to cancel weight ball sinks.View Buoyancy JAVA Applet.View animations produced by students at Poly Prep Country Day School in Brooklyn, New York.
5 View hydraulics explanation. B. Pascal’s PrinciplePascal’s Principlepressure applied to a fluid is transmitted unchanged throughout the fluidView hydraulics explanation.
6 B. Pascal’s Principle Platform: 1000 N = F2 F = 1000 N 250 m2 10 m2 A car weighing 1000 N sits on a 250 m2 platform. What force is needed on the 10 m2 plunger to keep the car from sinking?GIVEN:Platform:F = 1000 NA = 250 m2Plunger:F = ?A = 10 m2WORK:1000 N = F2250 m m2(1000 N)(10 m2)=(250 m2)F2F2 = 40 N
7 C. Bernoulli’s Principle as the velocity of a fluid increases, the pressure exerted by the fluid decreasesEX:airplane lift, curve balls
8 C. Bernoulli’s Principle Airplane liftCurve BallView airplane wings explanation.