1. Air Pressure

2. Air Pressure
Gravity pulls gas molecules in atmosphere toward Earth, causing air pressure

3. Experiment: Does Air have mass? Mass of balloon empty
Blow it up and find mass after
Is there a difference?

4. Air has mass!!!
Density = how much “stuff” fits in a certain space

5. (People density exercise!)
Density = how much “stuff” fits in a certain space
Density = Mass
Volume
(People density exercise!)

6. Who cares about density?
**Remember this fact**
Denser materials sink to the bottom

7. Air Pressure The weight of a column of air pushing on a surface area
**the atmosphere weighs as much as a school bus here at the school……so why aren’t you squished?** (mat and pull experiment)

8. Measuring air pressure
Barometer - an instrument that measures air pressure

9. Units of air pressure Inches of mercury Millibars
One inch of mercury = mb

10. Altitude and Air Pressure

11. *There’s less atmosphere on top of you!!!
As altitude ↑, air pressure ↓
(The higher you go, the lower the air pressure)
*There’s less atmosphere on top of you!!!

12. The less dense the air becomes
The higher you go
The less dense the air becomes

13. Why do your ears pop when you go up in altitude?

14. Soda can experiment!