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

2. Bernoulli’s Principle
Chapter 1
Bernoulli’s
Principle

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

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

5. Cross section of an Airplane Wing
Lower Pressure
Higher Pressure

6. Higher Pressure
Lower Pressure

7. How does Bernoulli’s Principle Explain….
how a vacuum cleaner works,
AND
how drinking through a straw works?

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

9. Chapter 2
Archimedes'
Principle

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

11. Archimedes’ Principle
The buoyant force on an object in a fluid is equal to the weight of the fluid displaced by the object.

13. 27.0 g Of Object Mass Of Object = 73.0 g L = 3.00 cm W = 3.00 cmAl
Volume = cm3
Of Object
H = 3.00 cm
Volume of H2O Displaced = 27.0 ml
Mass of H2O Displaced
Full beaker = g
Empty = g
27.0 g
100.0g
127.0g

14. Archimedes (Example #1)
Gravity = 73.0 g
Negative Buoyancy
Buoyant Force = 27.0 g

15. 135.0 g Of Object Mass Of Object = 6.0 g Balloon filled with AIR
Volume = cm3
Of Object
Volume of H2O Displaced = ml
Mass of H2O Displaced
Full beaker = g
Empty = g
135.0 g
100.0g
235.0g

16. Archimedes (Example #2)
Gravity = 6.0 g
Positive Buoyancy
Buoyant Force = g

17. The Boat begins to enter the water.
Mass Of Object = 20,000,000 g
Volume Of Object = 40,000,000 cm3
Because the amount of water displaced is still less than the boat’s mass, it continues to sink.
The Boat begins to enter the water.
Volume of H2O Displaced (so far)
= 10,000,000 ml
NEW Volume of H2O Displaced
= 20,000,000 ml
Mass of H2O Displaced
Full = 20,000,100.0 g
Empty = g
20,000,000 g
Mass of H2O Displaced
Full = 10,000,100.0 g
Empty = g
10,000,000 g
Now that they are equal, it stops sinking.
100.0g
10,000,100g
20,000,100g

18. Archimedes (Example #3)
Gravity
= 20,000,000 g
Neutral Buoyancy
Buoyant Force
= 20,000,000g

19. Chapter 3
Pascal’s
Principle

20. Force P = Area PRESSURE What is pressure?
It is a measurement of the force applied over an area.
Force
P =
Area

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

23. Which side of the problem do we have more information?
P = Force
Area
Area x P = Force x Area
Area
Force = Pressure x Area
Force = 10,000 N
Force?
Force = 10,000 N
Area =
15 cm2
Area =
500 cm2 A B
Force = 20 N x 15 cm2
cm2
P = Force
Area
Force = 300 N
P = 10,000 N
500 cm2
Which side of the problem do we have more information?
P = 20 N
cm2
P = 20 N
cm2