Physics (lantent heat)_____急!!!

[匿名]

2007-09-09 6:13 pm

我想問下點解latent heat可以用kinetic theory解釋?
1)係咪因為當a substance changes from solide to liquid的時候，partical becomes futher apart，而potential energy亦因而增加?
2)latent heat is the energy since it 不會導致溫度改變，係咪代表kinetic energy unchange?
3)我唔係好明白以下呢段文字的涵意，係關於latent heat同particle motion的，唔該解釋一下俾我聽__"Energy has to be supplied to oppose the attractive force among the particle. As a result,the potential energy of the particle increase."
4)如果我將0℃的水heat up至100℃，係呢個過程中potential energy會有改變嗎?

唔該曬*

回答 (1)

wmheric

2007-09-09 8:33 pm

✔ 最佳答案

1) Yes.
Latent heat is the energy, when supplied, increases the potential energy among particles, thus making particles become further apart.

2) Latent heat 本身就是 energy.
Yes. 溫度不變，即是 average kinetic energy of the particles remains unchanged.

3) 因為 particle 同 particle 之間有吸引力（attractive force），當你想轉佢個 state 時，energy 就會用來分開 particles 之間的吸引力，而 particles 分得越開，state 就會由 solid -> liquid -> gas。
這個吸引力其實是 potential energy 的成因。如果 energy supply 突然消失了，particles 便會互相吸引而縮短它們之間的距離。

4) 如果 state 沒有改變，一直都是液態的水，那麼 average separation between particles 維持不變，（average 的吸力不變，）所以 potential energy 也維持不變。

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