Original Project
Energy: Forms, Transformation, Transfer, and Conservation
Item NG003003: Gravitational potential energy is transformed into motion energy and thermal energy when coasting down a hill on a bicycle.
A girl is riding her bicycle down a hill without pedaling. She speeds up as she goes down the hill, and the tires get a little warmer. What energy transformations happen while she is going down the hill?
- Motion energy (kinetic energy) is transformed into gravitational potential energy and thermal energy.
- Gravitational potential energy is transformed into motion energy (kinetic energy) and thermal energy.
- Gravitational potential energy is transformed only into motion energy (kinetic energy).
- No energy transformations are involved while she is going down the hill.
- Distribution of Responses
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 1490 | 3031 | 49% |
| Grades | |||
| 6–8 | 861 | 1908 | 45% |
| 9–12 | 626 | 1114 | 56% |
| Gender | |||
| Male | 719 | 1460 | 49% |
| Female | 748 | 1525 | 49% |
| Primary Language | |||
| English | 1376 | 2749 | 50% |
| Other | 73 | 196 | 37% |
- 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 …lifting an object increases the stored energy in the gravitational field between that object and Earth (gravitational potential energy) compared to that for the object at Earth’s surface; when the object falls, the stored energy decreases and the object’s kinetic energy increases. (5, 121)
- PS3.B For example, the friction that causes a moving object to stop also results in an increase in the thermal energy in both surfaces…