ASPECt
Energy: Forms, Transformation, Transfer, and Conservation
Item NG011004: When a box slows down as it slides across the floor, the motion energy of the box decreases and the thermal energy increases because the motion energy is converted into thermal energy.
A student shoves a box, and it slides across the floor. As the box slides across the floor, the box slows down, and both the box and the floor get a little warmer. What happens to the kinetic energy (motion energy) and the thermal energy of the box as it slows down and comes to a stop and why?
- The kinetic energy of the box decreases to zero, and its thermal energy increases because the kinetic energy is converted into thermal energy.
- The kinetic energy of the box decreases to zero, and its thermal energy stays the same because kinetic energy is used up and is not converted into thermal energy.
- The kinetic energy of the box stays the same, and its thermal energy increases because new energy in the form of thermal energy is made.
- Both the kinetic energy and the thermal energy of the box decrease to zero because an object has energy only when it is moving.
Answer Choice |
Overall |
Grades |
Gender |
Primary Language |
|||||
|---|---|---|---|---|---|---|---|---|---|
| n = 2945 |
4–5 n = 78 | 6–8 n = 1394 |
9–12 n = 1473 |
Male n = 1382 |
Female n = 1486 |
English n = 2669 |
Other n = 193 |
||
| A. | The kinetic energy of the box decreases to zero, and its thermal energy increases because the kinetic energy is converted into thermal energy. | 42% | 32% | 37% | 47% | 44% | 40% | 42% | 38% |
| B. | The kinetic energy of the box decreases to zero, and its thermal energy stays the same because kinetic energy is used up and is not converted into thermal energy. | 21% | 22% | 22% | 19% | 21% | 20% | 21% | 18% |
| C. | The kinetic energy of the box stays the same, and its thermal energy increases because new energy in the form of thermal energy is made. | 20% | 18% | 22% | 19% | 20% | 21% | 20% | 22% |
| D. | Both the kinetic energy and the thermal energy of the box decrease to zero because an object has energy only when it is moving. | 17% | 27% | 19% | 15% | 16% | 19% | 17% | 21% |