ASPECt
Energy: Forms, Transformation, Transfer, and Conservation
Item RG116002: The electrostatic potential energy of the system of two positively charged objects decreases as the distance between then increases, and the kinetic energy of the moving particle increases and the distance increases..
A positively charged particle is held close to a stationary positively charged object in a vacuum chamber in which all the air has been removed.
When the particle is released, it moves away from the stationary object.
How do the electrostatic potential energy of the particle-object system and the kinetic energy of the small particle change as the particle moves away from the stationary object (before it hits the wall of the vacuum chamber)?
- The electrostatic potential energy of the system increases, and the kinetic energy of the particle decreases.
- The electrostatic potential energy of the system decreases, and the kinetic energy of the particle increases.
- The electrostatic potential energy of the system and the kinetic energy of the particle both increase.
- The electrostatic potential energy of the system stays the same, and the kinetic energy of the particle increases.
- Distribution of Responses
- Scale Score for Item Difficulty
(200[Easy]-800[Difficult]) - 509
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 428 | 1124 | 38% |
| Grades | |||
| 4–5 | N/A | N/A | N/A |
| 6–8 | 229 | 666 | 34% |
| 9–12 | 199 | 458 | 43% |
| Gender | |||
| Male | 208 | 546 | 38% |
| Female | 207 | 560 | 37% |
| Primary Language | |||
| English | 373 | 988 | 38% |
| Other | 38 | 110 | 35% |
- Disciplinary Core Ideas
- PS3.A Motion energy is properly called kinetic energy; it is proportional to the mass of the moving object and grows with the square of its speed.
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.