We will invent a category of "stuff" that passes from one ball to the next. Can we reach agreement on what the properties of this stuff are? What rules it seems to follow? Can we convince ourselves that it's something "real?" Under what conditions?

Lecture on speed, momentum, energy, movement - the range of models we have - and a focus on energy for today and tomorrow.

Lecture on energy conversions.

Lecture on conservation, our commitment to energy conservation.