三年级英语作文：硬币为什么可以浮在水面
时间：2020-11-15 10:33:24 来源：达达文档网 本文已影响 人 
今天，我无意间同学听说，硬币可以浮在水面上。我可不相信，决心试一试。说罢，我就向同学们请教了方法。放学后，我飞快地跑回家，一心想着做实验。
Today, my classmates overheard that coins can float on the water. I don"t believe it. I"m determined to try. After that, I asked my classmates for advice. After school, I raced home, thinking of doing experiments.
我回到家，开始着手准备材料：脸盆、水、干毛巾。这些都准备就绪后，我就开始试验了：第一步先把手和硬币擦干净，我擦干手后，正想擦硬币，呀，硬币呢，怎么不见了？我摸摸口袋也没有。哎！瞧我这木瓜脑袋，连硬币都没有那还浮什么啊。我急忙上楼拿了几个一元的硬币，然后把一个最亮的给擦干净。第二步，将硬币小心地放在食指的指尖上，正面朝上。第三步，把手轻轻地放进水里，食指最后着水，让硬币的反面碰到水就行了。可是，这一次的实验我却失败了。我想应该是因为我不小心碰到了水。第二次，我重新准备好，开始做实验了，可我刚把硬币放好把手拿开，硬币却又沉下去了。我气急了，嘴里嘀咕着：“还说硬币能浮起来呢？真是吹牛。”转念一想：“不妨多试几次，万一真能成功，好在同学面前‘炫耀炫耀’”。
When I got home, I started to prepare materials: washbasin, water, dry towel. When all this was ready, I began to experiment: the first step was to wipe the hands and coins clean. After I dried my hands, I was trying to wipe the coins. Ah, how can the coins disappear? I didn"t touch my pocket. Hey! Look at my papaya head. It doesn"t even have coins. What"s floating. I hurried upstairs to get some one yuan coins, and then I wiped the brightest one. Second, place the coin carefully on the tip of the index finger, facing up. The third step is to gently put your hand into the water, and the index finger finally touches the water, so that the reverse side of the coin touches the water. However, I failed in this experiment. I think it"s because I accidentally touched the water. The second time, I prepared again and began to do experiments, but I just put the coin in place and took it away, but the coin sank again. I was so angry that I muttered, "what about the coins floating? What a boast. " Turn to think: "might as well try several times, in case it can really succeed, good in front of the students" show off.".
我接二连三试了几次都没有成功。这时，表姐刚好来找我，见我正在做“浮硬币”，就赶紧说：“你不该用这么大的硬币，应该找一个一角的小硬币。”“哦，是这样啊。”我恍然大悟。说完，我马上从抽屉里找出一个小硬币，将它擦干净。开始试验了，我一试，小硬币就浮起来了。“硬币浮起来了，硬币浮起来了！”我高兴地跳着，叫着。此时，表姐比我还得意，仰着头问我：“你知道这是什么原因吗？”我想了想，又摇了摇头，这下可把我难住了。她呢，是更得意了。我“求”她告诉我，她才把原因说出来：原来，液体的表面好像一张绷紧的橡皮膜。各部分之间存在着相互牵引的拉力，这种力叫做表面张力。如果我们轻轻地把一枚硬币平放在水面上，由于硬币较轻，水的表面张力能承受住它对水面的压力，所以能浮在水面而不下沉。
I tried again and again without success. At this time, my cousin just came to me and saw that I was making "floating coins". She hurriedly said, "you shouldn"t use such a large coin, you should find a small coin with a dime." "Oh, that"s right." It dawned on me. With that, I immediately found a small coin from the drawer and wiped it clean. The experiment began. As soon as I tried, the small coin floated. "The coin is floating, the coin is floating!" I jumped and cried happily. At this time, my cousin was more proud than I was. She looked up and asked me, "do you know why?" I thought about it and shook my head, which made me puzzled. She is more ()proud. I "begged" her to tell me, she just said the reason: originally, the surface of the liquid looks like a tight rubber film. There is a pulling force between the parts, which is called surface tension. If we gently place a coin on the surface of the water, because the coin is light, the surface tension of the water can bear the pressure on the water, so it can float on the water without sinking.
看起来，只要你肯观察，生活中处处有科学。
It seems that as long as you are willing to observe, there is science everywhere in life.
