Ch 3 4 Motion Forces VII Forces in
- Slides: 11
Ch. 3 & 4 Motion & Forces VII. Forces in Fluids (Ch. 8. 5) Archimedes’ Principle u Pascal’s Principle u Bernoulli’s Principle u
A. Archimedes’ Principle l Fluid § matter that flows § liquids and gases l Buoyancy § the ability of a fluid to exert an upward force on an object immersed in it
A. Archimedes’ Principle l Bouyant Force § upward force exerted by a fluid on an immersed object § bouyant force > weight balloon rises § bouyant force < weight balloon sinks § bouyant force = weight balloon floats
A. Archimedes’ Principle l Archimedes’ Principle § the bouyant force on an object in a fluid is equal to the weight of fluid displaced by the object Not More water needs water is to displaced betodisplaced in order toorder cancel to to Veryenough little water needs be displaced in cancel weight ball sinks. ball floats lower in the water. on surface. View Buoyancy JAVA Applet. View animations produced by students at Poly Prep Country Day School in Brooklyn, New York.
B. Pascal’s Principle l Pascal’s Principle § pressure applied to a fluid is transmitted unchanged throughout the fluid View hydraulics explanation.
B. Pascal’s Principle l A car weighing 1000 N sits on a 250 m 2 platform. What force is needed on the 10 m 2 plunger to keep the car from sinking? GIVEN: WORK: Platform: F = 1000 N A = 250 m 2 Plunger: F=? A = 10 m 2 1000 N = 250 m 2 F 2 10 m 2 (1000 N)(10 m 2)=(250 m 2)F 2 = 40 N
C. Bernoulli’s Principle l Bernoulli’s Principle § as the velocity of a fluid increases, the pressure exerted by the fluid decreases § EX: airplane lift, curve balls
C. Bernoulli’s Principle Airplane lift View airplane wings explanation. Curve Ball
C. Bernoulli’s Principle Funnel Demos View funnel explanation. View inverted funnel explanation.
C. Bernoulli’s Principle l Venturi Effect § fluids flow faster through narrow spaces causing reduced pressure § EX: garden sprayer, atomizer, carburetor
C. Bernoulli’s Principle Venturi Effect - Atomizers View atomizer explanation.
