Item NG087004: A roller skater, who coasts down one hill and up another hill that is the same height as the first hill, will not have enough energy to reach the top of the second hill because some of her motion energy is transformed into thermal energy.
A student wearing roller skates is standing at the top of a hill. She wants to find out if she can get to the top of the other side just by coasting. She coasts down the hill and then up the other hill without pushing. The second hill is the same height as the first hill. As she coasts, her skates and the ground get a little warmer.
Will she have enough kinetic energy (motion energy) to coast to the top of the second hill? Why or why not?
- Yes, she will have enough kinetic energy to coast to the top of the second hill. Even though some of her kinetic energy will be transformed into thermal energy, she will gain enough kinetic energy as she goes down the steep side of the first hill to make it to the top of the second hill.
- Yes, she will have enough kinetic energy to coast to the top of the second hill because the second hill is the same height as the first hill. The thermal energy that the skates and the ground gain does not affect how much kinetic energy she has.
- No, she will not have enough kinetic energy to coast to the top of the second hill. She will use up her kinetic energy as she coasts, and the kinetic energy she uses up is not related to the thermal energy that the skates and the ground gain.
- No, she will not have enough kinetic energy to coast to the top of the second hill. Some of her kinetic energy is transformed into thermal energy of the skates and the ground, and no new energy is added to the system (the girl, the skates, and the ground).
Answer Choice |
Overall |
Grades |
Gender |
Primary Language |
||||
---|---|---|---|---|---|---|---|---|
n = 1093 |
4–5 n = 0 | 6–8 n = 648 |
9–12 n = 445 |
Male n = 498 |
Female n = 558 |
English n = 958 |
Other n = 95 |
|
A. | 33% | N/A | 37% | 28% | 32% | 36% | 35% | 24% |
B. | 23% | N/A | 24% | 23% | 25% | 22% | 22% | 29% |
C. | 18% | N/A | 16% | 20% | 17% | 18% | 18% | 21% |
D. | 25% | N/A | 23% | 29% | 26% | 24% | 25% | 25% |