Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s...

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Buoyancy, Density, and Water

Transcript of Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s...

Page 1: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Buoyancy, Density, and

Water

Page 2: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Properties of Fluids

Overview:

Archimedes’ Principle Pascal’s Principle Bernoulli’s PrincipleBoyle’s Law

Page 3: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Density is the mass of a substance per unit volume (usually measured in grams per milliliters, g/ml).

Buoyancy is the upward force that a fluid exerts on an object less dense than itself.

Page 4: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Q: How do ships float?

Page 5: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

A: A greater force is pushing up on the ship than the weight

force pushing down.

This supportive force is called buoyant force.

Page 6: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

If the buoyant force is equal to the object’s weight, it will float.

Page 7: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

If the buoyant force is less than the object’s weight, it will sink.

Page 8: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Bouyant force was explained by Archimedes and it became known as Archimedes’ Principle.

Archimedes was a Greek mathematician who lived around the 3rd century

B.C.

Page 9: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Archimedes’ Principle states that

an objects weight will cause the object to sink while at the

same time displacing the fluid.

Page 10: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.
Page 11: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

If the weight of the water displaced

becomes equal to weight of the object,

it floats.

Page 12: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

If the weight of the water displaced becomes less than the weight of the

object, it sinks.

Page 13: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Q: Why is this principle

important?

Page 14: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

A: Properties of fluids ultimately determine the design of ships, airplanes, cars, and hydraulic machines.

Page 15: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Water exerts pressure in all direction.

Consider swimming in a pool. The deeper you go the more pressure you feel.

Page 16: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Pressure is a force exerted on an object per unit area.

Page 17: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

As you know pressure is not exclusive to

liquids. The earth’s atmosphere exerts pressure all around

you.

Page 18: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Pascal’s Principle

Pascal was a French scientists who lived in

the 1600’s. He discovered a property of fluids now known as

Pascal’s Principle.

Page 19: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

According to Pascal’s Principle pressure applied to a fluid is

transmitted throughout the fluid.

Page 20: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

For example when you squeeze a tube of

toothpaste at one end, what happens?

Page 21: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Why?

Pressure is transmitted throughout the fluid

toothpaste.

Page 22: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Calculating Forces Using Pascal’s Principle

Pressure = Force/Area = F/A

In a system, P1 = P2::

F1 = F2

A1 A2

Page 23: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Pressure System

Page 24: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

As the velocity of a fluid increases, the pressure exerted by the fluid decreases.

Bernoulli’s Principle

Page 25: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Bernoulli’s Principle

Page 26: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Boyle’s Law

As a gas is squeezed into a smaller space, its particles will strike the walls more often, increasing its pressure.

The opposite is also true.

Page 27: Buoyancy, Density, and Water. Properties of Fluids Overview: Archimedes’ Principle Pascal’s Principle Bernoulli’s Principle Boyle’s Law.

Calculating Pressure Using Boyle’s Law

P1 V1 = P2 V2