Student reasoning about electrostatic and gravitational potential energy: An exploratory study with interdisciplinary consequences

This paper describes an investigation into student reasoning about potential energy in the context of introductory electrostatics. Similar incorrect reasoning patterns emerged both in written questions administered after relevant instruction and in one-on-one interviews. These reasoning patterns are also prevalent in responses to questions posed about gravitational potential energy in the context of universal gravitation in introductory mechanics. This finding is relevant for interdisciplinary research, because many courses in multiple disciplines first introduce the concept of electric potential energy in analogy to gravitational potential energy. The results suggest that in introductory courses students do not gain an understanding of potential energy that is sufficiently robust to apply in more advanced physics courses or in disciplines other than physics, in which students must frequently reason with energy in the context of interactions between atoms and molecules.

Figure 1

The two charged blocks problem. Students were asked to identify whether potential energy was increasing, decreasing, or staying the same when (a) two like-charged blocks are pushed toward one another and (b) two oppositely charged blocks are pushed away from one another. In each case, the blocks begin and end at rest.

Figure 2

The orbits problem. Students were asked to determine whether the kinetic and potential energy of the spacecraft-Earth system each increase, decrease, or stay the same as the spacecraft moves from point A to point B.