1. AIR TESTING CENTERS CONTINUED Pen or pencil Find out activity sheet from yesterday on the table

2. Station One: Diving Paper  What did you notice in the cup?  Did the paper stay dry?

3. Explanation  The glass is filled with air whether it is right side up or upside down  No where for the water to flow into the cup!  AIR TAKES UP SPACE!!!!

4. Application  Examples of where we might see this happening in our lives?  Why is it important that we know air takes up space?

5. Applications Continued  Flipping a canoe  Goggles when scuba diving  Under water welding  Driving underwater - 1.8 km-long tunnel crossing opened in 1972. - First road link between Kowloon and Hong Kong Island

6. Station Two: Magic Seal  Why do you think the index card stuck to the cup?

7. Explanation  Air outside of cup pressed on the card with more force than the weight of the water.  Atmospheric pressure is larger and thus holding the water inside the cup  Almost like a vacuum

8.  Different Demonstration, same idea.  Can you explain it this time?

9. Explanation  Vacuum  Air is pushing more than the water weight of the water ALSO:  The attraction of water molecules (cohesion) hold the water droplets together.  The molecules are joined together to form a thin membrane between each opening in the mesh

10. Applications  Why is it important to know about air pressure?  Where might we see this property of air in our everyday lives?

11. Air Pressure Application  Siphoning  Drinking straws  Syringe

12. Strength Test  What do you think is holding the newspaper down?

13. Explanation  Air pressure is pushing down on the paper  Pressure of air is about (1kg/cm 2 )  Roughly 15 lbs/in 2  Atmospheric pressure is lowest at sea level  AIR EXERTS PRESSURE!

14.  Why are we not crushed by air pressure then?

15. Balancing Act  What about the balloons help you balance the meter stick?

16. Explanation  Size of each balloon is roughly the same amount  Same mass in each balloon  AIR HAS A MASS!!  What will happen if you pop one of the balloons?  How much does air weigh?

17. Application For Mass of Air  Engineers need to know that air has a mass when constructing air filtration systems

18. Exit Slip  On the piece of paper provided  - Name thee properties of air discussed  - Example of these three properties in everyday life  If you have any questions, or are wondering about something please write it on the back