The goal of the 7th grade unit is for students to design contraptions that incorporate the maximum number of different kinds of energy transformations, and to explain how energy flows through these contraptions. The unit identifies the various types of energy with different detectable properties, such as kinetic energy with motion, thermal energy with temperature, and elastic energy with deformation. It emphasizes that although there are many types of energy, they are really just different manifestations of the same thing. Energy is involved in every known phenomena and it is always conserved, even though often this appears to be wrong because certain transformations have been ignored.
The learning goals for this unit are:
There are different types of energy.
Energy can be transformed from one type to another.
Energy cannot be created or destroyed. Whenever some energy seems to disappear from a place, some will be found to appear in another.
Atoms and molecules are perpetually in motion. Increased temperature means greater average kinetic energy due to increased random motion of atoms and molecules.
Heat is the energy lost or gained by a system as a result of a temperature difference between that system and its surroundings.
Most energy transformations result in heat being transferred into or out of the system in which the transformations took place.
Different ways of obtaining, transforming, and distributing energy have different social, economic, and environmental consequences.