Thermal Expansion (James Rice)

Author

James Rice

Principle(s) Illustrated

"Thermal expansion is the tendency of matter to change in shape, area, and volume in response to a change in temperature. Temperature is a monotonic function of the average molecular kinetic energy of a substance. When a substance is heated, the kinetic energy of its molecules increases." - Thermal Expansion, Wikipedia

Standards

NGSS SEP

• Developing and Using Models

• Using Mathematics and Computational Thinking

• Constructing Explanations and Designing Solutions

NGSS CCC

• Cause and Effect

• Scale, Proportion and Quantity

• Energy and Matter

• Structure and Function

NGSS Disciplinary core idea standards

• PS3.A: Definitions of Energy

• At the macroscopic scale, energy manifests itself in multiple ways, such as in motion, sound, light, and thermal energy.

• PS3.D: Energy in Chemical Processes

• Although energy cannot be destroyed, it can be converted to less useful forms—for example, to thermal energy in the surrounding environment.

• ETS1.A: Defining and Delimiting an Engineering Problem

• Criteria and constraints also include satisfying any requirements set by society, such as taking issues of risk mitigation into account, and they should be quantified to the extent possible and stated in such a way that one can tell if a given design meets them. (secondary)

Questioning Script

Prior knowledge & experience:

The liquid in thermometers moves up when temperature increases and down when temperature decreases.

Root question:

• What will happen to the volume of various materials when they are heated, and by how much?

Target response:

• Different materials expand by different amounts for the same change in temperature according to the thermal expansion formula.

Common Misconceptions:

• Magic - No, really, people think this

• Material is growing because energy makes things grow, like plants and people.

• A heated ring will have a smaller inner diameter than a cool ring because they think the material swells in all directions, but in reality the material, because it also expands longitudinally around its circumference, the ring actually gets bigger.

Photographs and Movies