ASPECt
Energy: Forms, Transformation, Transfer, and Conservation
Item NG007004: When you let go of a stretched rubber band, the elastic energy that the rubber band has when it is stretched is converted into motion energy.
A student stretches a rubber band and then lets it go.
The rubber band flies across the room. Which of the following describes what must have happened in terms of the energy of the rubber band?
- The elastic potential energy of the stretched rubber band was converted into kinetic energy (motion energy) when the student let it go.
- The rubber band had the same amount of elastic potential energy the entire time, but it gained kinetic energy (motion energy) when the student let it go.
- The stretched rubber band did not have any energy, but it gained both kinetic energy (motion energy) and elastic potential energy when the student let it go.
- The elastic potential energy that the stretched rubber band had was used up when the student let it go, and the rubber band did not have any energy as it flew across the room.
- Distribution of Responses
- Scale Score for Item Difficulty
(200[Easy]-800[Difficult]) - 469
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 650 | 1102 | 59% |
| Grades | |||
| 4–5 | N/A | N/A | N/A |
| 6–8 | 356 | 643 | 55% |
| 9–12 | 294 | 459 | 64% |
| Gender | |||
| Male | 357 | 560 | 64% |
| Female | 285 | 529 | 54% |
| Primary Language | |||
| English | 586 | 971 | 60% |
| Other | 52 | 110 | 47% |
- Disciplinary Core Ideas
- PS3.B When the motion energy of an object changes, there is inevitably some other change in energy at the same time.
- NRC Framework
- PS3.A Any change in potential energy is accompanied by changes in other forms of energy within the system, or by energy transfers into or out of the system.