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TOEIC・英語 大学生・専門学校生・社会人

自分の回答と照らし合わせて確認したいので、答えがなにになるかどなたか教えてください。 解説もあると助かります。

5 A Matter of Taste Reading Passage 042 At the age of just 22, Jamie Oliver became well known across the UK as "The Naked Chef." He called himself this not because he cooked wearing no clothes, but because he wanted to simplify food preparation so that everybody could follow his recipes. He wanted to "strip down" the idea of cooking. Since then he has had numerous TV shows, published 50 many books, and has become a household name in the UK. Today, one of the activities Jamie Oliver is best known for is his great effort to improve the school dinners that children eat every day. One day, he visited the kitchen of a typical London secondary school, and he was shocked to see how much processed junk food the kids were given to eat each day. Fat and sugar levels were extremely high, and nutritional values very 10 low. The "turkey twizzler" became the symbol of these unhealthy meals: processed meat containing 21.2% fat and only 34% actual turkey. Oliver ran the school kitchen for one year and tried to show that it was possible to serve healthy meals on a limited budget—and that kids actually enjoyed eating them. His mission was to radically change the eating habits of children in that school, and across the country. 150 200 15 20 25 CULTIES 250 His project (the "Feed Me Better" campaign) has had some influence on school dinners in the UK. After watching the documentary Jamie's School Dinners, 271,677 people signed a petition calling for healthier school meals. This led the Prime Minister to agree to spend 280 million pounds (about 37 billion yen) on school dinners, to ban some junk food from school menus, and to create a School Food Trust to provide support and advice for people preparing school meals. Research, by the way, shows that children who stop eating sugary, fatty food and instead eat Oliver's school dinners are better behaved in class, and they get higher test 300 scores, too. 350 Of course, the project has had some problems. At first, many students (and even parents) resisted the removal of the junk food they were so used to. In one famous instance, some parents were passing local takeaway food to their children through the school fence. Also, schools that followed the plan for a while were often found to gradually drift back into bad habits. After all, it is easier and cheaper to just give the kids junk food. However, Oliver's efforts represent a positive start, and with obesity becoming such a huge problem (see Unit 4), 400 it's a very necessary start.

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物理 大学生・専門学校生・社会人

電磁気学の問題になります。 問3以降全く分かりません。教えていただけると助かります。

真空中で円周にそって流れる電流 (円電流) がつくる磁場, および, 円電流と等価な磁気モーメントについて 考える. 一般に,真空中で電流素片Ⅰds が距離 R だけ離れた点につくる磁束密度 dB は dB = Ho Ids x 4π R² で与えられる (ビオサバールの法則) ここで, Mo は真空の透磁率,Iは電流の大きさ, ds は電流の方向に とった微小変位ベクトル, hは電流素片からその点に向かう方向の単位ベクトルである. (1) 下図 (a) に示されるように、座標原点を中心とする π-y平面上の半径aの円周にそって図に示された方 向に電流Iが流れているとき, 点A(0, 0, h) における磁束密度の向きと大きさを求めよ. ただし, ん > 0 とする. (2) 下図(b)に示されるように、座標原点におかれた大きさがpでz軸方向の磁気モーメントが,点A(0, 0, h) に作る磁束密度の向きと大きさを求めよ。 ただし, 磁気モーメントとは正負の磁荷の対が微小な距離だ け離れているものであるが, んはその距離に比べて十分大きいとする. 問 (1) と問 (2) の結果より, 半径aの円電流Iは,十分遠方からみると, 大きさがHoTa²Iの磁気モーメント と等価であると考えられる.このことを利用して,次に, 真空中で円運動する荷電粒子について考える。 ただ し, 古典力学の範囲で考えることとし, この円運動による電磁波の輻射は無視できるとする. (3) 座標の原点に電荷g (> 0) が固定されている。 下図 (c) に示すように、質量がmで-gの電荷を持つ質 点が, g-y平面上で原点の周りを図に示す方向に一定の角速度で円運動している. この円の半径をと する. この質点の円運動を円電流とみなすことにより, 十分遠方からみた等価な磁気モーメントの向き と大きさ on を求めよ。 ただし, 真空の誘電率を e とする. (4) 下図 (d) に示すように、 磁束密度が B (> 0) で軸方向の一様な弱い磁場中で、 問 (3) と同じ問題を考 える ただし, 質点の円運動の半径は問 (3) と同じと仮定する. このときの十分遠方からみた等価磁 気モーメントの大きさを Pen とし, Apo PeB-Poo をBの1次までの近似式として求めよ. 2 •A(0,0,h) Z •A(0,0,h) y Pr (b) C 2 dan dal g 'T

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