Thermal Expansion and SLR (Paulo Villafana)

Title: Thermal Expansion and SLR.

Principle(s) Investigated: Thermal Expansion, Kinetic Energy, States of Matter, Specific Heat

Standards: Past in the appropriate NGSS standards.

• 5-PS1-1. Develop a model to describe that matter is made of particles too small to be seen.
• 5-PS1-2. Measure and graph quantities to provide evidence that regardless of the type of change that occurs when heating, cooling, or mixing substances, the total weight of matter is conserved.
• 5-PS1-3. Make observations and measurements to identify materials based on their properties.

Materials: Small plastic water bottles (3bottles per group), straw, water, heat source, ice bath

Procedure:

1. Have the modified bottle ready before arriving to class. Instructions for making modified bottles.
2. Fill the bottles with water to the same height each bottle (for visual effect use two different food coloring preferably red and blue)
3. Pass out hot plates with a beaker filled with water and ice bath to each group
4. Have students place the red water bottle in the beaker with hot water, and the blue water bottle into the iceboat
5. Wait 5 minutes for the heat transfer to take place (here you I will show a video about SLR)
6. After 5 minutes the water level will change
7. Have students TIPS what happened
8. Explain what happened, molecules have more KE therefore they expand. Phet simulation could be used to help visualize what the water molecules are doing.
9. Discuss its implication to SLR
10. EXTEND Fill a ballon with water and another with air.
11. Burn the balloon with air and water
12. Have students do TIPS as to what they saw and how it ties into the previous demonstration
    1. Explain. More than 90 percent of the warming that has happened on Earth over the past 50 years has occurred in the ocean. Source

Student prior knowledge: Students should know

• A molecule with more KE have more velocity
• Collisions transfer energy

Explanation: Explanation of the experiment (Link to PPP)

Thermal Expansion and Energy

• Thermal expansion is due to an increased in Kinetic Energy of an individual molecules.
• An increase in KE increases the velocity of a molecule (as the molecule can not change its mass)
• Increasing the velocity creates more collision between molecules, increasing the volume the molecules take up.

Phet Simulation0C 25C 100C

Questions & Answers: Give three thought-provoking questions and provide detailed answers.

1. You make a cup of tea to pair your lovely biscuit. You take a sip of the tea, but it is SOOO HOOT! You get the teaspoon and stir your tea. Does your teaspoon expand as you stir the tea?

As your tea spoon begins to heat up, the spoon expands! BUUUT the spoon is not big enough to notice the heat expansion... or is there?

2.One of Mr. Cesar's favorite hobby is sitting in 205F sauna! To get the sauna up to proper temperature, Mr Cesar pours water on the rocks. When the water turns into steam, the sauna door tends to open. Why does this happen?

As the water vaporizes into steam, the steam molecules have more KE than other air molecules, because steam is at minimum of 212F. The thermal expansion of air pushes the door open. =[

What role does thermal expansion play in SLR?

Thermal expansion contributes to SLR, as the ocean gets warmers the water level rises.

Applications to Everyday Life:

Heat expansion joints are installed on bridges!

During hot months gaps between the teeth are less than during colder months.

What would happen if the bridges were not allowed to expand or contract?

Combustion Engines

Engineers must consider thermal expansion properties of parts inside engines!

In the yellow box are the turbines which spin when hot combusted air passes through them. The turbine blades expand during use. Engineers design the turbine housing with thermal expansion in mind!

Damage to the blades would cause a catastrophic failure!!!

Applying Thermal Expansion to Sea Level Rise

• More than 90 percent of the warming that has happened on Earth over the past 50 years has occurred in the ocean1
• Thermal Expansion of water has and will continue contributing to Sea Level Rise

Current SL

SLR by 10 ft

Photographs:

Ice Room Temp. Hot water

Note the water level!