1. Behavior of Fluids
Chapter 3
Section 2

2. Reminder…Fluids
A substance that continually deforms (flows) under an applied stress
Includes liquids, gases, & plasmas

3. Reminder…Force
A push or pull

4. (P) pressure = (F) force ÷ (A) area
force exerted on a surface divided by the area where the force is exerted - the unit is Pa (Pascal) or N/m2
Formula:
P = F ÷ A
(P) pressure = (F) force ÷ (A) area

5. Pressure Example/Demo
Stand Up!

6. Atmospheric Pressure the force of air pushing down on Earth
we do not feel this pressure b/c the downward & upward forces are equal (Balanced Pressure)
Figure 18 Page 120
How does the picture to the right demonstrate air pressure?

7. Variations in Atmospheric Pressure
 altitude →  atmospheric pressure

8. Pascal’s Principle
Force is applied to a confined fluid, an increase in pressure is equally distributed to all parts of the fluid
P = F ÷ A OR F = P x A

9. Bernoulli’s Principle
 Speed →  Pressure

10. Charles’ Law
 Temp →  Pressure

11. Boyle’s Law
 Volume →  Pressure

12. Pressure Summary 
PRESSURE
force 
area
temp.
speed
Volume
studying

13. Buoyant Force the upward force on an object in a liquid
due to greater pressure at deeper depths (like greater pressure at lower altitudes)
If buoyant force is > the weight of an object, it floats
If buoyant force is < the weight of an object, it sinks

14. Archimedes' Principle
The buoyant force on an object is equal to the weight of the fluid displaced by the object