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物理 高校生

問5、類題4の答えしかなく解き方がのっていないので教えてください😭

F - 物体は静止 物体は正の加速度で 加速度運動をする ▼表1 摩擦係数(出発:学第2) 接触物体 (面の状態) 静止 摩擦力 最大摩擦力 FoμN ガラスとガラス (乾燥) 6.54 F=f 鉄鋼と 動摩擦力 F'='N 0.78 9.42 (乾燥) 静止摩擦力 F 鉄鋼と鉄鋼 0.00 (塗油) 木と木 0.6 0 物体を引く力 (乾燥) ▲図34 物体に加える力を増していくときの摩擦力の変化 あら 問5 質量 10kgの物体が, 粗い水平な台に置かれている。 物体と台の間の静止摩 は 0.50, 動摩擦係数は0.10である。このとき, 最大摩擦力の大きさを求めよ。また、 静止状態から,この物体に水平に力を加えてその大きさをONから徐々に大きくし ていく。 力が30N 及び 50N になったとき, この物体にはたらく摩擦力の大きさを それぞれ求めよ。 重力加速度の大きさを9.8m/s^とする。 例題 7 粗い斜面上での物体の運動 【解説】 粗い斜面上に質量mの物体を置き, 傾斜角0 をしだいに 大きくしていったところ, 傾斜角が0。 となったときに物 体は滑りだした。 物体と斜面の間の静止摩擦係数をと してμを0 の式で表せ。 最大摩擦力はFo=μN で表される。 N(N) 力の関係 斜面に垂直上向きを正, 重力加速度の大きさをg, 垂直抗力 の大きさをNとして、斜面に垂直な方向の力のつり合いより, N=mg cos b。 ... ① N-mg cosbo=0 mg sin 斜面に平行上向きを正として,斜面に平行な方向の力のつり合いより、 uN-mgsind= 0 ... ② ② に ① を代入して, μmg cos Omgsinbo = 0 比例する。 よって, u= mg sin 00 mg cos lo =tan00 Note 粗い斜面上に置かれた物体は、静止摩擦係数 と左の関係を満たす傾斜角を超えると りだす。この摩擦角といい、摩擦角& から静止摩擦係数を求めることができる。 類題 4 質量mの物体が傾斜角30°の粗い斜面上に置かれて静止している。 物体と斜面の間 の静止摩擦係数を重力加速度の大きさを」として、このときの静止摩擦力を 2 求めよ。 また, 物体を斜面に平行下向きに動きださせるのに必要な力の最小値を求 求めよ。さらに、平行上向きに動きださせるのに必要な力の最小値を求めよ。

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英語 高校生

英語の長文です どこに文法表現があるか知りたいです! よろしくお願いします。

5 UNIT3 Reading Passage 10 15 20 20 25 30 Listening When important events are happening around the world, most people turn to traditional media sources, such as CNN and BBC,¹ for their news. However, during the invasion of Iraq by the United States and its allies in early 2003, a significant number of people followed the war from the point of view of an anonymous² Iraqi citizen who called himself "Salam Pax" (salam means "peace" in Arabic, and pax means "peace" in Latin). Salam Pax wrote a diary about everyday life in Baghdad during the war, and posted it on his web site. Pax's online diary was a kind of web site known as a "blog." Blogs, short for "web-logs," are online diaries usually kept by individuals, but sometimes they are written by companies and other groups of people. They are a rapidly growing type of web site on the Internet. There are estimated to be several hundred thousand blogs on the Internet, and with the popularity of other social media sites, the number of people writing online about their lives continues to grow. may find A blog differs from a traditional web site in several ways. Most importantly, it is updated much more regularly. Many blogs are updated every day, and some are updated several times a day. Also, most blogs use special software or web sites which are specifically aimed at bloggers, so you do not need to be a computer expert to create your own blog. This means that ordinary people who computers difficult to use can easily set up and start writing their own blog. In 2003, the Internet company AOL³ introduced their own blogging service, enabling its 35 million members to quickly and easily start blogging. There are many different kinds of blogs. The most popular type is an online diary of links, where the blog writer surfs the Internet and then posts links to sites or news articles that they find interesting, with a few comments about each one. Other types are personal diaries, where the writer talks about their life and feelings. Sometimes these blogs can be very personal. There is another kind of blogging, called "moblogging," short for "mobile blogging." Mobloggers use cell phones to take photo's, which are posted instantly to the Internet. When the content and images posted online involve news subjects, mobloggers become citizen journalists. In fact, the Korean web site OhMyNews was a well known source for articles from international citizen journalists. However, in 2010, OhMyNews stopped posting new articles. Instead, it is now a blog site where citizen journalists can choose what makes the headlines, or just share ideas about how regular people are changing the news world. Anyone who visits the web site of a big media company can clearly see how the idea of blogging has changed the reporting of news. Quite often, a list of reader comments follow news articles. It seems that the news is becoming less like a report or a lecture, and more like a conversation, where anyone can join in. CNN, BBC Cable News Network, British Broadcasting Corporation anonymous not named; unknown 3 AOL America Online

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英語 高校生

英語の長文です。 文法表現のあるところが知りたいです。 よろしくお願いします。

UNIT 1 5 Reading Passage 10 15 20 20 25 Listening There are more than 37,000 known species of spiders in the world in a wide variety of shape's and sizes! The largest spiders in the world live in the rain forests of South America and are known by the people who live there as the "bird-eating spiders." These spiders can grow up to 28 centimeters in length- about the size of a dinner plate, and, as their name suggests, have been known to eat small birds. In comparison, the smallest species of spider in the world is native to Western Samoa. These tiny spiders are less than half a millimeter long — about the size of a period on this page and live in plants that grow on mountain rocks. - Some people like to keep spiders as pets, particularly tarantulas, which are native to North America and can live for up to twenty-five years, Most people, on the other hand, do not like touching spiders, and a significant number of people are afraid of them, mainly because of their poison. However, despite their bad reputation, only thirty of the 37,000 known species of spiders are deadly to humans. Spiders actually provide benefits to humans, by catching and eating harmful insects such as flies and mosquitoes. - - The main thing that makes spiders different from other animals is that they spin web's to catch the small insects they feed on. The unique silk of a spider's web is produced by special organs found spider web is five times in the lower part of the spider's body. It is light, elastic, and strong stronger than steel. Additionally, it is completely biodegradable. This means that the web will making it perfect for uses completely decompose¹ and eventually return to nature over time such as making fishing nets. Some people have tried to raise spiders commercially in order to collect the silk these spiders produce, but no one has ever really managed to make a go of it. One reason why these businesses never stand a chance is because it takes 670,000 spiders to produce half a kilogram of silk, and all of these spiders need living insects for their food. In addition, spiders are usually solitary² animals, and need to be kept alone. Researchers at an American company working together with two U.S. universities may have found a solution to making artificial spider web. Using genetically modified silkworms,³ the company hopes that in the long run it will be able to make large quantities of very light, very strong fiber for medical as well as other uses. Additionally, because the manufacture of the artificial web is from living silkworms, the industry potentially would be non-polluting and less harmful to the environment

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