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更新1:
Answer is A
物理phy~~~~~
2010-04-16 6:31 pm
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回答 (2)
2010-04-16 10:41 pm
✔ 最佳答案
A : 因為補償摩擦 即係冇淨力係佢身上 , 佢勻速行所以動能不會增加其他答案的解釋
B.明顯佢向下行緊 , 所以勢能減少
C.小車的動能不變,但勢能減少 所以佢地之和減少, 減少左既能量去左作功抵消 犘擦力
D.補償摩擦即摩擦力=mgsin@
2010-04-16 7:41 pm
C
Friction compensated runway eliminates the effect of friction
you can then assume there is no energy loss
A&B: correct, as PE loss = KE gain
C: no energy loss, then by conservation of energy, how can total sum decrease?It is impossible
D: correct, there is still friction, but its effect is eliminated
Friction compensated runway eliminates the effect of friction
you can then assume there is no energy loss
A&B: correct, as PE loss = KE gain
C: no energy loss, then by conservation of energy, how can total sum decrease?It is impossible
D: correct, there is still friction, but its effect is eliminated
收錄日期: 2021-04-23 20:39:55
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100416000051KK00317