ASPECt
Energy: Forms, Transformation, Transfer, and Conservation
Item RG125002: Decreasing the distance between two positively charges particles, increases the amount of electrostatic potential energy in the system.
Two charged particles are positioned as pictured in Figure 1 below. A student moves the particles so that the distance between the two particles is decreased as shown in Figure 2. He secures the particles in place so neither can move. The strength of the charges remains the same the whole time.
Which of the following statements correctly describes the change in electrostatic potential energy of the system of two particles from Figure 1 to Figure 2?
- The electrostatic potential energy has increased.
- The electrostatic potential energy has decreased.
- The electrostatic potential energy has not changed.
- Additional information is needed to determine the change in electrostatic potential energy.
- Distribution of Responses
- Scale Score for Item Difficulty
(200[Easy]-800[Difficult]) - 499
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 500 | 1132 | 44% |
| Grades | |||
| 4–5 | N/A | N/A | N/A |
| 6–8 | 290 | 682 | 43% |
| 9–12 | 210 | 450 | 47% |
| Gender | |||
| Male | 263 | 551 | 48% |
| Female | 226 | 560 | 40% |
| Primary Language | |||
| English | 457 | 1018 | 45% |
| Other | 37 | 102 | 36% |
- Disciplinary Core Ideas
- PS3.A A system of objects may also contain stored (potential) energy, depending on their relative positions.
PS3.C When two objects interacting through a field change relative position, the energy stored in the field is changed. - NRC Framework
- Energy is also stored in the electric fields between charged particles and the magnetic fields between magnets, and it changes when these objects are moved relative to one another.