ASPECt
Energy: Forms, Transformation, Transfer, and Conservation
Item NG104002: Assuming no energy transfer between a ball and the track it is moving in, the speed of the ball will be the same before and after rolling down into and up out of a dip because the total amount of energy in the system does not change.
Imagine a ball on a track where no energy is transferred between the ball and the track or between the ball and the air around the ball. The ball goes past Position 1, then down and up a dip on the track, and past Position 2. Position 1 and Position 2 are at the same height.
Will the ball be going faster, slower, or at the same speed at Position 2 compared to Position 1? Why? (Remember that no energy is transferred between the ball and the track or between the ball and the air around it.)
- Faster, because new energy in the form of kinetic energy (kinetic energy) will be made when the ball goes down the long side of the dip
- Slower, because kinetic energy (motion energy) will be used up when the ball goes up the steep side of the dip
- The same speed, because the amount of kinetic energy (motion energy) that the ball has will remain the same the entire time it was moving along the track
- The same speed, because the total amount of energy in the system (ball and track) does not change as the ball moves along the track
- Distribution of Responses
- Scale Score for Item Difficulty
(200[Easy]-800[Difficult]) - 572
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 371 | 2939 | 13% |
| Grades | |||
| 4–5 | N/A | N/A | N/A |
| 6–8 | 146 | 1560 | 9% |
| 9–12 | 225 | 1379 | 16% |
| Gender | |||
| Male | 181 | 1354 | 13% |
| Female | 178 | 1501 | 12% |
| Primary Language | |||
| English | 342 | 2647 | 13% |
| Other | 23 | 203 | 11% |