1. BEHAVIOR OF GASES

2. The amount of force exerted per unit area
PRESSURE
The amount of force exerted per unit area

3. Pressure = force / area

4. Unit on pressure is PASCAL (Pa)
PASCAL = Newton / meter2

5. The atmosphere on Earth exerts pressure on everything.
How much pressure?
About 100,000 Pa!!! (~100kPa)

6. 100,000N = weight of a large truck
This means that in every square meter, 100,000N of pressure is exerted.
100,000N = weight of a large truck

7. As you move farther from the earth, the pressure becomes MUCH less.
Which layer would have the least pressure? Why?

8. Pressure depends on how often the particles hit the surface
More times = more pressure

9. Characteristics of Gases
Negligible Volume (very compressible)
Gases are in constant motion
Collisions are completely elastic
No forces off attraction or repulsion
Kinetic energy of a gas is directly proportional to the temperature

10. BOYLE’S LAW
For a given amount of gas at a constant temperature the volume of the gas varies inversely with pressure.

11. CHARLES’S LAW Volume of a gas increases if the temperature increases
(pressure staying constant)

12. How could Charles’s Law be used to explain why hot air balloons fill up.

13. If temperature is constant when V decreases then P _________
INCREASES

14. If pressure is constant when T increases then V _________

15. What happens when you relax in a swimming pool?
You float!!! Duh…but why?

16. BUOYANCY
The ability of a liquid or gas to push up on an object placed in it
(you in a swimming pool)

17. If the buoyant force is greater than the weight, then object FLOATS!
If not…it sinks.

18. DENSITY
The relationship of the mass (weight) to how much space it takes up (volume)

20. ARCHIMEDE’S PRINCIPLE
The buoyant force on an object in a fluid is equal the weight of the fluid displaced