#### Focus Questions

• What is pressure?
• What are the properties of presssure?
• What variables affect pressure?
• What is equilibrium?
• Can pressures be at equilibrium?
• What happens if pressures aren't at equilibrium?
• How can pressure be represented in diagrams?
• How can systems, subsystems, and models be used in explanations?
• How can science be used to answer real world questions?

### Physical

Background

Matter occupies space. No two objects can occupy the same space at the same time. Matter can be pushed by solid objects, liquids and gases that have a greater force. There is a lot of air above us pushing down. Solids, liquids, and gases exert more pressure at the bottom than at the top. Pressure inside a closed system with a fluid substance will exert a force in the fluid in all directions.

• Pressure is a force exereted over an area.
• Gases and liquids flow when they exert unequal pressure on each other.

### Science practices

Evidence can be collected and used with logical explanations to understand and predict changes in the world.

### Crosss cutting concepts - Systems & system models, structure & functions, stability and change

Stability and change - when objects exert equal forces on each other they are at equilibrium. When objects are not in equilibrium one will displace the other.

Systems & system models - Drawings can be created to represent and explain scientific ideas.

#### Activity Sequence

1. could start with water in a plastic bag and pencil pierce activity
2. Individually answer the focus questions in a science journal
3. Blow up a balloon
4. Draw a diagram to explain the pressures on the balloon
5. Blow up a ballon inside a two-liter plastic bottle
6. Draw a diagram to explain the pressures on the balloon and bottle.
7. Blow up the balloon inside a two-liter plastic bottle with a straw
8. Draw a diagram to explain the pressures on the balloon and bottle
9. Put a tied balloon with air in it into a two-liter plastic pop bottle and use the fizz keeper® to add air to the bottle
10. Draw a diagram to explain the pressure on the balloon and bottle
11. Look inside a balloon
12. Draw a diagram to explain the pressure on the balloon and bottle.
13. Water pressure and air with a lid
14. Water pressure and air without a lid
15. Cartesian diver

#### Activity Descriptions

Activity 1 Focus Questions

Materials:

Procedure:

1. Ask students to answer the following questions individually in their science notebooks.What is pressure?
2. What are the properties of presssure?
3. What variables affect pressure?
4. What is equilibrium?
5. Can pressures be at equilibrium?
6. What happens if pressures aren't at equilibrium?
7. How can pressure be represented in diagrams?
8. How can systems, subsystems, and models be used in explanations?
9. How can science be used to answer real world questions?

Activity 2 Blow up a Balloon

Materials: Balloon

Procedure:

1. Ask the students to blow up a balloon and explained what happened.
2. Keep it untied because they will use it again.

Activity 3 Draw a diagram to explain the pressures on the balloon.

Let the air out of the ballooon. Explain what happened. Why did the air leave?

Activity 4 Blow up a ballon inside a two-liter plastic bottle

Materials: Balloon, two-liter bottle,

Procedure:

Activity 5

Draw a diagram to explain the pressures on the balloon and bottle.

Activity 6
Blow up the balloon inside a two-liter plastic bottle with a straw
Materials: :
Balloon, two-liter bottle, straw
Procedure:
1.

Activity 7
Draw a diagram to explain the pressures on the balloon and bottle

Activity 8
Put a tied balloon with air in it into a two-liter plastic pop bottle and use the fizz keeper® to add air to the bottle
Materials:
Balloon, two-liter bottle, fizz keeper®
Procedure:
1.

Activity 9
Draw a diagram to explain the pressure on the balloon and bottle

Activity 10
Look inside a balloon
Materials:
Balloon, two-liter bottle with two tops
Procedure:
1.

Activity 11
Draw a diagram to use to answer the following questions for activity 10:

Is there pressure?
What are the properties of presssure(s)?
What variables are effecting the pressure(s)?
Are the pressures at equilibrium?
Activity 12

Air pressure and change of volume

Materials: 2 liter plastic bottle, hot water, lid.

Procedure: Fill the bottle with hot water, dump the water, cap the bottle quickly and allow it to stand.

Activity 12

Air pressure and water

Materials: 2 liter bottle, push pins.

Procedure: Fill the bottle with water, cap the bottle, stick two pins into the bottle one about an inch below the water level and the other below the first. Remove one pin replace, remove the other, remove both, and then try with the cap unscrewed. What if the two holes were both two inches below the water level?

Activity 13

Pressure changes with the amount of matter

Materials 2 liter bottle, push pins, measuring device.

Procedure: Fill the bottle with water, make two - three pin holes at 2 cm intervals from the bottom of the bottle, put masking tape on each hole, remove one piece of tape from a hole and collect the water for a predetermined amount of time, refill the bottle and repeat for other holes.

Activity 14

Pressure changes the volume and density of matter.

Materials: Glass eye dropper, 2 liter plastic bottles with cap.

Activity: Make the eye dropper rise and fall in a bottle of water.