Report, Discuss, and Reflect (~2.5 hrs.)
Make diagrams and annotate them using arrows and words to describe where heat is transferred. Then imagine that you could look at these experiences through a “molecular microscope.” Describe how you think heat transfer would affect the particles’ energy of motion.
Heat Transfer in Your Life - Where do you see heat transfer by conduction in your everyday life? This week, describe a few examples of conduction in the Heat Transfer in Your Everyday Life section of your journal.
By Wednesday in the Discussion Forum
Post your report from the Assignment
By Saturday in the Discussion Forum
Read and discuss your colleagues’ reports.
The discussion question asks you to synthesize all the pieces of your science investigation. Your responses to the question and to one another should draw upon and reference your work with temperature and heat transfer:
After the discussion wraps up, look back at this week's goals, read What's the Big Idea?, and reflect on your work this week.
What's the Big Idea?
The big idea in this session is energy transfer by conduction using both macroscopic and particle models of conduction.
On a macroscopic scale conduction is a phenomenon most readily observed in solid materials in which energy is transferred from regions of higher temperature to regions of lower temperature.
On a particle scale, a region of higher temperature is a region in which the motion of the molecules about their equilibrium positions is more agitated. This causes neighboring molecules to begin to move in a more agitated fashion. In this way the energy of motion propagates throughout the material.
In some solid materials such as metals, there are many electrons that are not tied to molecules but are free to move anywhere within the body of the material. Despite the fact that the electrons have very little mass, they can carry energy from one part of the object to another.
One way to think about energy moving without mass moving is to imagine a bedspring in which you jiggle one corner. Pretty soon the entire bedspring is jiggling. What is happening is that the energy is being transported across the bedspring even though every spring remains essentially in place.
Another way to think about energy being transferred without the movement of mass is to think of a long row of dominos standing on edge. Knock the end one down and all the rest will fall. A certain amount of energy has moved through the entire row of dominos even though no domino did so.
Questions for Reflection
- What do you think is the most important thing you learned from this week's activities?
- What surprised you? Why?
- What questions are you left with?