What Makes Something Feel Warm What Makes Something Feel Warm? Modeling Energy Transfer: A Macroscopic and Particulate View

Lesson Warm Up Why do mothers tell their kids to put on a sweater?  What is it about the sweater that keeps them warm? This winter was soooo cold. My mother told me to “put on a sweater, because I’m cold.”

THE BIG QUESTION Be more explicit about relating the problem to the students kitchen Choices are: Wooden Butcher Block Granite countertop Aluminum baking pan Glass bowl Plastic container with cold water Kitchen towel

Exploration #1: Observe the Properties of Materials Explore the properties of the tiles: In groups of 2, answer questions 3-5 (Step 1) In groups of 2, answer questions 6-8 (Step 2) In groups of 4, answer question 9 (Prepare a white board that summarizes your ideas about temperature) 20 minutes Distribute white boards – as groups are working help group the participants for the share ideas about temperature: Clearly temperature is NOT a measure of heat. If it were, both tiles would melt the ice equally. So, here is the place where you can define temperature as the measure of average kinetic energy of the particles. A great demo to show the correlation between temperature and average KE, is putting a drop of blue or green food coloring in a large beaker of cold water and a large beaker of hot water. Notice how quickly the dye diffuses. At this stage all students should be clear that temperature is a measure of average KE NOT heat.  

Exploration #2: Observe Ice on Material Think about melting ice: Work through questions 10-12 Individually fill answer ALL of #13 In your groups, complete Step 5. Prompt for step 5 are on the student guide, but overall see next slide

Modeling Energy Transfer A Macroscopic View and Engineering Practices Build a particle model that can be used to explain the interaction between the tile and the ice. Represent your model using a set of particulate drawings that describe the interactions between ice particles and tile particles. Put participants into groups (2-5 participants) depending on attendance. Provide them whiteboards or poster paper for presenting their ideas. This is question 2 in the student guide. While groups work, move through the room and questions/challenge group models.

Exploration #2: Observe Ice on Material PREPARE A WHITEBOARD BUILD CONSENSUS SHARE IDEAS