1. Chapter 9 :Many technologies are based on the properties of Fluids

2. What we will learn this chapter
Pascal’s law states when force is applied in an enclosed system, the increase is transmitted equally to all parts of the fluid
There are both natural and manufactured fluid systems

3. Fluid Systems Definition: Examples
A fluid system is a group of parts, including at least one fluid, that interact with each other and function together as a whole.
Body’s circulatory system
Respiratory system
Movement of sap in trees

4. Pascal´s Law
Blaise Pascal in the mid-1600s, investigated what happens when force is applied to a closed system
Pascal Law:
States that when force is applied to an enclosed fluid, the increase in pressure is transmitted equally to all parts of the fluid.
A liquid that fills a bottle exerts pressure in all directions

5. Transmitting pressure in a fluid
A fluid exerts pressure on any surface it touches
Squeezing a bottle increases the pressure equally everywhere in the bottle

6. What is a confined fluid?
Any fluid in a closed system
The fluids can move around the system, but cannot leave the system
Ex: blood, air mattress

7. Calculating Pascal The unit for pressure is Pa (Pascal)
You can determine pressure if you know the force and the area.
If force increases --> pressure increases
If area increases --> pressure decreases

8. Formula for Pressure Formula: Pressure (P) = Force (F) Area (A)
Force (f) =Area x Pressure
Area = Force
Pressure

9. Sample Problem: Pressure
An aquarium is filled with water that weighs N. If the base of the aquarium has an area of 1.6 m², what pressure does the water exert on its base?

10. Answer
Unit for pressure is Pa
G= Force= 10, 000 N Area = 1.6m² R = p? A= F/A S= P=10 000N 1.6m² =P = 6250 Pa S= The pressure excerted on the base is 6250 Pa

11. Sample Question: Force
If the atmospheric pressure is Pa and you are holding your hand, the atmosphere is exerting a force on your hand. If the area of your palm is 0.006m², calculate the force on your hand.

12. Answer:
Unit for force is N
G: Pressure= Pa Area= 0.006m² R:F? A: F= AXP S: F= x 0.006m²= N S= The force of my hand would be 607 N

13. Sample Question: Area
The weight of water in a glass is 4.9 N. If the water is exerting a pressure of 1700 Pa on the bottom of the glass, what is the area of the bottom of the glass?

14. Sample Question: Area
Unit for are is m2
G: Force= 4.9N P=1700Pa R: A? A: A= F/P S: A= 4.9N/1700Pa = m2 S: The area of the bottom of the glass is m2