Bernoulli’s, Pascal’s, & Archimedes’ Principles

Bernoulli’s, Pascal’s, & Archimedes’ Principles Principles of Fluids

Bernoulli’s Principle • As the Velocity (speed) of a fluid increases, the Pressure exerted by the fluid decreases • Why?

This explains one of the forces that make an Airplane Fly Airplanes have FOUR basic forces acting on them: LIFT LIFT THRUST THRUST DRAG DRAG GRAVITY GRAVITY LIFT can be explained using Bernoulli’s Principle.

Cross section of an Airplane Wing Lower Pressure Higher Pressure

Venturi Effect As the size of a fluid’s pathway decreases, the velocity of the fluid increases.

Buoyant Force • The upward force of a Fluid exerted on an object. • What is the downward Force exerted on an object? Gravity

Archimedes’ Principle • The buoyant force on an object in a fluid is equal to the weightof the fluid displaced by the object

Mass = 20g Archimedes (Example #1) Volume = 20ml Mass of Fluid= 20g

Gravity = 20 Buoyant Force = 20 Archimedes (Example #1) Neutral Buoyancy

Mass = 50g Archimedes’ (Example #2) Volume = 20ml Mass of Fluid= 20g

Gravity = 50 Buoyant Force = 20 Archimedes (Example #2) Negative Buoyancy

Mass = 30g Archimedes’ (Example #3) Volume = 60ml Mass of Fluid= 60g

Gravity = 30 Buoyant Force = 60 Archimedes (Example #3) Positive Buoyancy

Pascal’s Principle • Pressure applied to one place of a fluid is transmitted unchanged throughout the fluid.

Force P = Area Pascal’s Principle What is pressure? What type of fluid works best for this principle? Explain your answer. Liquid

Force ? Force = 10,000 N A B Pascal’s example Area of A = 8 cm2 Area of B = 50 cm2

Force P = Area P = 200 N A B cm2 Break down the problem: 1st solve for P in B 10,000 N P = 50 cm2

Force P = Area F = P x A 8 cm2 A B x Break down the problem: 2nd solve for F on A 200 N cm2 F = F = 1600 N

Bernoulli’s, Pascal’s, & Archimedes’ Principles