1. Pressure in a Jar
What do you think will happen to the water in the tube when I squeeze the jar?
Record your predictions under Part 1 of page 45 of your lab book.

2. Investigation 8 part 1 Air Pressure Inquiry
Day 40
Investigation 8 part 1
Air Pressure Inquiry

3. Syringes and Pressure
Remember the activity with the syringes and tubing
Describe the investigation
The air was compressed when the plunger was squeezed
The blue foam cube became smaller because the air inside it was compressed

4. Air-Pressure Inquiry Plastic jar that is tightly closed
The inside glass is half filled with water
A stopper with tubing is pushed tightly into the glass bottle

5. Pressure in a Jar
In your groups: Assemble a pressure indicator as instructed.
Materials:
-rubber stopper
- clear plastic tube
-Glass bottle
- Plastic jar

6. Gently Squeeze the Jar…
What happens to the water level in the tube?
Surprised?
Water level in tube goes down!!
Explain why this happens!

7. Water molecules can not be squeezed closer together - it’s a liquid
Results
Air molecules are squeezed closer together
When you squeeze the plastic jar…
Water molecules can not be squeezed closer together - it’s a liquid

8. Results
Why does the water in the tube go down when you push on the sides of the plastic jar?
When you squeeze the plastic jar…

9. The volume in the plastic jar is less
Why it happens…
Increases the pressure in the plastic jar
Molecules have less room to move around so they bang into each other and the sides of the jar more often
When you squeeze the plastic jar…
The volume in the plastic jar is less

10. The air inside the top of the glass bottle is also compressed
Air takes up less room
leaving an empty space in the glass bottle
Which can not change its shape
Why it happens…
When you squeeze the plastic jar…
The air inside the top of the glass bottle is also compressed

11. Why it happens…
When the volume of air in the glass bottle is compressed
The water flows up the straw to fill the empty space
When you squeeze the plastic jar…

12. Question 2- Page 45(LB)
Decreased the volume in plastic jar and increased air pressure
Air in the glass bottle is compressed - leaving an empty space in the glass bottle
Water flowed from the tube to fill the space previously filled with air in the glass bottle

13. Question 3- Page 45 (LB) There would be less pressure
Air in the glass bottle would expand
Pushing the water up the tube

14. Multimedia Gas in a syringe simulation
Compare the syringe system to the pressure indicator you built.

15. Density What happened to the volume?
It decreased
What happened to the number of molecules?
Stayed the same.

16. Density
If the number of molecules stayed the same, what happened to the total mass of the molecules?
It stayed the same.
If the volume decreased and the mass stayed the same, what happened to the density of the air?
The density increased