Investigation 4: Kinetic Energy November 4-5

Explain gas compression and expansion. Warm Up Explain gas compression and expansion.

Warm Up Gas compresses when force is applied. Gas expands when the force is withdrawn. The number and size of the particles does not change. The space between the particles changes.

Learning Target I can demonstrate and explain what happens to air when it is heated and cooled.

Frayer Vocabulary Cards Give each person at your table a copy of Frayer model instruction sheet. I will pass around tape to tape this into your notebook. Give each person two blank Frayer templates.

Frayer Model

Frayer Model Complete a Frayer template for compression and one for expansion. We will tape them into your science notebook.

Expectations Conversation: None Help: Raise your hand and wait for teacher. Continue to work while waiting for me. Activity: Complete 2 Frayer cards. Movement: None Participation: Students complete Frayer cards in 7 minutes. Work quietly without help from neighbors.

Air as Particles Gas compresses when force is applied. Gas expands when force is withdrawn. Gases are composed of widely spaced individual particles in constant motion. There is nothing between particles except space.

Air in a Syringe Are there more particles in a volume of gas when it is compressed? Does a volume of compressed gas weigh more? Do the particles get smaller as the volume of gas gets smaller? Does the space between the particles get smaller as gas compresses?

Why is it hard to pull up on the plunger in a sealed syringe when the plunger starts all the way down? There is very little air in the syringe to start with so there are not very many particles to push up on the syringe. The particles on the outside are pushing. The resistance you feel is the force of atmospheric pressure pushing the plunger down!

Air in a Syringe, NB Page 63 Using a pencil, complete page 63.

Page 65 Answer all questions quietly No talking No getting out of seats. Raise your hand if you have a question.

Page 65

Gas Gases are composed of individual particles. The particles are not connected and they move freely through space traveling straight line until they run into something. When the particles collide, they bounce off and keep moving in a straight line. Air particles move about 670 mph.

Gas Because gas particles have space between them, they can be compressed. When you stop applying force to the syringe, the air articles inside the syringe push up on the plunger and it moves up to where it started.

Multimedia Watch quietly Raise your hand if you have a question.

Text book: Page 16 to 22 Listen and follow along as selected reader reads out loud. You must follow along. I will use popsicle sticks to randomly select reader.

Science lab NB page 69 Answer all questions in complete sentences. I will check for completion at the beginning of next class. Do not work on this during class.

Gas Cooling and Heating Answer the pre-assessment on hot and cool gas. Write your answer in complete sentences and be descriptive so that you explain your thinking.

Gas Cooling and Heating What would happen if I heated and cooled the air in this bottle? Your assignment is to show a class of 4th graders what happens when air when it is heated and cooled. Try to find a way that to show what happens to a volume of air when it is heated or cooled.

Materials Bottle and cap 2 large cups for water 1 foam cup 1 balloon 1 stopper and tubing 1 cup of bubble solution 1 tray

Rules!!! Place nothing inside the bottle. No crushing, folding, or otherwise modifying the bottle. Share the group items so that everyone in the group gets a chance to demonstrate what happens when a volume of air is heated and cooled.

Science lab NB page 71 Try several ways to demonstrate the heating and cooling of air. Diagram the demonstration that you think is best. Write an explanation that will help fourth graders understand what happens when air is heated and cooled.

Share Results How did you use a balloon? How did you use the plastic tube? How did you use the bubble solution? What other setups did you try to demonstrate what happens to air when it heats and cools?

Cool and Hot Air When a volume of gas gets hot, its volume increases. The process of increasing volume is called expansion. When a volume of gas gets cold, its volume decreases. The process of decreasing volume is called contraction.

Cool and Hot Air What caused the balloon to inflate? What caused the balloon to deflate? What caused the tube to blow bubbles when it was underwater? What caused water to go up the tube when it was underwater? What caused the plastic bottle to crush when it was placed in cold water?

Exit Slip Describe in detail how you demonstrated that gas expands and contracts.