ASPECt
Energy: Forms, Transformation, Transfer, and Conservation
Item RG177001: When a girl and skateboard move at the same speed, the girl has more kinetic energy because the she weighs more than the skateboard.
A 70 kg girl is riding her 3 kg skateboard along a level surface. She jumps as shown in the figure below, lands on the skateboard, and continues along at the same speed.
When the girl is in the air above her skateboard, does the girl or the skateboard have more kinetic energy (motion energy) and why?
- The skateboard has more kinetic energy than the girl because the girl gave the skateboard her energy.
- The girl has more kinetic energy than the skateboard because the girl is alive but the skateboard is not.
- The girl has more kinetic energy than the skateboard because the girl weighs more than the skateboard.
- The skateboard and the girl have the same amount of kinetic energy because they are traveling at the same speed.
- Distribution of Responses
- Scale Score for Item Difficulty
(200[Easy]-800[Difficult]) - 537
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 2630 | 10998 | 24% |
| Grades | |||
| 4–5 | 135 | 687 | 20% |
| 6–8 | 1147 | 5618 | 20% |
| 9–12 | 1348 | 4693 | 29% |
| Gender | |||
| Male | 1387 | 5214 | 27% |
| Female | 1184 | 5525 | 21% |
| Primary Language | |||
| English | 2318 | 9620 | 24% |
| Other | 242 | 1061 | 23% |