本人想問一d野。

The hissing sound is produced because of two main reasons:

1. the formation of water vapour from the cooling water pushes back the surrounding air rapidly, thus producing a sound;

2. the surface of the metal cools down and contracts suddenly, producing a stress on the metal beneath the surface, thus causing a sound.

冷縮熱脤原理law
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^^

當燒熱左既金屬放入水後,這樣燒熱左既金屬温度就會下降,發出'zia'一聲.我想這個原理是熱賬冷縮.

好明顯
就係燒熱左既金屬有既ENGERY轉左形式
佢變左令水蒸發既Energy(latent heat of vaporization)同sound energy
如果d水唔係100度..仲會有d energy用黎增加水既溫度到100度之後先蒸發..即係specific heat capacity of water..公式大概係

energy of increase temperature +energy of vaporization+ sound energy('zia'一聲)= energy of metal