ASPECt
Energy: Forms, Transformation, Transfer, and Conservation
Item RG075003: When two repelling magnets are let go, some of the potential energy that the system of magnets had when they were being held close together is converted to kinetic energy when let go.
A person places two magnets on a table and starts to bring them closer together until she feels them repel each other. Then she lets go of one of the magnets. When she lets go of the magnet, it moves away from the other magnet. Where did the kinetic energy (motion energy) of the magnet that is moving come from?
- The magnetic force that was between the two magnets was transformed into the kinetic energy of the magnet that is moving.
- Some of the potential energy that the system of magnets had when they were being held close together was converted to kinetic energy when she let go of the magnet.
- Gravity gives magnets potential energy, and some of this energy was transferred to the magnet she let go of and converted to kinetic energy.
- The magnet that she let go of created its own kinetic energy by moving.
Answer Choice |
Overall |
Grades |
Gender |
Primary Language |
||||
|---|---|---|---|---|---|---|---|---|
| n = 1130 |
4–5 n = 0 | 6–8 n = 634 |
9–12 n = 496 |
Male n = 518 |
Female n = 592 |
English n = 987 |
Other n = 121 |
|
| A. | 30% | N/A | 29% | 32% | 31% | 29% | 30% | 31% |
| B. | 37% | N/A | 38% | 36% | 39% | 36% | 38% | 32% |
| C. | 21% | N/A | 21% | 21% | 19% | 23% | 21% | 26% |
| D. | 11% | N/A | 12% | 10% | 11% | 12% | 11% | 12% |