https://online2.tingclass.net/lesson/shi0529/0009/9697/74.mp3
https://image.tingclass.net/statics/js/2012
Take two nails and scrape them togethervigorously. Now touch the place you were scraping.It’s hot! Let them cool and try it again. It’s hotagain! You could do this all day and the nails wouldnever stop growing hot. If heat were a liquid, therewould have to be an infinite amount of it even in atiny nail. What’s the better answer? Heat is ameasure of kinetic energy. Kinetic energy meansthe amount of motion the molecules in the nailhave, or how much they jostle against each other.The hot spoon heats your hand not becausesomething invisible is being poured in, but because the fast-jostling molecules of the spoonhit the molecules in your hand and start them jostling too. In the case of the nails, all that’sneeded to produce more heat is to start jostling those molecules again after they’ve calmeddown. You won’t ever run out of heat.
以兩個釘子和他們一起大力刮。現(xiàn)在觸摸的地方,你被刮。它的熱!讓他們冷靜,并再次嘗試。它的熱了!您可以這樣做,整天和指甲永遠不會停止增長熱點。如果熱的液體,它是一個無限量,即使在一個微小的指甲。什么更好的答案嗎?熱是一種動能的措施。動能手段的運動量在指甲的分子,或有多少,他們對彼此爭搶。熱勺加熱你的手不會因為看不見的東西正在澆筑,但由于勺子快速沖撞分子的分子打在你的手,開始他們過于擁擠。在指甲的情況下,所有的需要產(chǎn)生更多的熱量是開始再次沖撞這些分子后,他們已經(jīng)平靜下來。你永遠不會用完的熱量。