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物理 高校生

物理の質問です。リードライトの電磁気で、 (4)のFはx軸の正の向きってあるんですけど、なんで正の向きかわかりません。 電流Iって図の時計回りだから、フレミングの左手の法則で中指を金属棒に沿うと親指はx軸の負の向きになると思うんですが。(T_T)

122 第4編 電気と磁気 基本例題 76 磁場を横切る金属棒に生じる誘導起電力 真空中に金属レールが水平に置かれ,その上を金属棒がなめらかに移動でき るようになっている。 金属棒の長さは1〔m〕 で, レールの間隔に等しい。 図1 のように,xyz軸をとる。 このとき,磁束密度B [T] の磁場がx軸の正の向き に加えられている。 また, 金属棒の抵抗は R [Ω] である。 b 図2のように, 端子 a,b 間に起電力 E [V] の電池 (内部抵抗0) を接続したところ, 金属棒は動き始めた。 x軸の正の向きに速さ 〔m/s] で動いている金属棒について (1) 両端に発生する誘導起電力の大きさ V〔V〕 を求めよ。 流れる電流の大きさI 〔A〕と向きを求めよ。→ 19 (3) 加わる力の大きさ F〔N〕を求めよ。 43132&(2 MBS (4) 十分な時間が経過して金属棒の速さが一定になったときの速さv 〔m/s] を求めよ。 Ⅰ (1) おもりの速さ(一造 (1) V=vBl〔V〕 (2) キルヒホッフの法則Ⅱより E-V=RI よって I= E-vBl R 〔A〕,軸の正の向き 件の図2で電池をつかっているから Let's Try! 111 磁場を横切る導線に生じる誘導起電力 B a レール y Z 2 26 金属棒 抵抗 R x 図 a E 141. で降下する。 >>> 141 1 ○磁場 $v[m/s 指針 金属棒に生じる誘導起電力の大きさはBl〔V〕 である。 向きは、レンツの法則と右ねじの法則とから判断する。 解答 z 軸の負の向きの磁場をつくる向きに誘導起電力 (3) F=IBl= E-vBl R [BU [N] Vが発生 (レンツの法則)。 V の向きはEの向きと反対 になる (右ねじの法則)。 (4)Fはx軸の正の向きでアフレミングの左手の法則), 棒 は加速され ”の増加とともにVも増す。 VがEに 達すると, ② ③ 式より I=0, F = 0 となり, 速さは ひで一定になる。 ③ 式で, v=vo のとき F=0 より E E-vo Bl=0 よって = (m/s] BU 軸の 正の向き 図2 車の軌

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英語 高校生

教えて下さると嬉しいです(><)

Circle the correct answer for each question. A. likely to be jealous of someone 1. You are more 2. Which do many people decorate at Christmas time? 3. Which are people more accustomed to? 4. Which of these is a weapon? 5. Which of these flows? a. rich b. poor a. a feast b. a tree a. spending money b. receiving awards b. a rifle b. water b. ruin it b. confused b. a feast b. a contract a. a recruit a. being punished b. getting a reward B. Complete the paragraph with items from the box. Two items are extra. 6. What would profit do for a business? 7. Which would people rather be? 8. Which would you invite friends to share with you? 9. Which would you sign? 10. Which would few people enjoy? discovered resembled establishing rights faced status a. an empire a. an insect a. help it a. excited a. a contract grief the rest of (9) by Roy's son and (10) heir took over Many people change countries during their life, but one man has (1) (2) himself by his own country. During World War II, the UK built a number of artificial platforms in the sea to contain (3) that would be used to fight off invaders. After the war, the soldiers left these platforms and they were forgotten - until 1967. In that year, a British man, Roy Bates, (4) one of the platforms and announced he had started his own country, called Sealand. This surprised people in the UK, who believed they had the (5) - Bates and (6) to leave the platform. However, Roy (8). made a name for weapons to the platform. orders In 1968, a court decided that the UK had no power over Sealand. Just like other places with the that the platform was in international waters. of a country, Sealand, has its own stamps, coins, and passports. It is controlled 'Prince' Michael, and is home to a large Internet business. the people on the island (his family), (7) in 11 - 15 69

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英語 高校生

教えて下さると嬉しいです(><)(><)

A. Circle the correct answer for each question. likely to be jealous of someone 1. You are more 2. Which do many people decorate at Christmas time? 3. Which are people more accustomed to? a. rich a. a feast b. a tree a. spending money b. receiving awards a. an empire b. a rifle a. an insect b. water a. help it b. ruin it a. excited b. confused a. a contract b. a feast a. a recruit b. a contract a. being punished b. getting a reward B. Complete the paragraph with items from the box. Two items are extra. 4. Which of these is a weapon? 5. Which of these flows? 6. What would profit do for a business? 7. Which would people rather be? 8. Which would you invite friends to share with you? 9. Which would you sign? 10. Which would few people enjoy? discovered resembled establishing rights called Sealand. faced status - Many people change countries during their life, but one man has (1) (2). This surprised people in the Bates and (6) to leave the platform. However, Roy (8). (9) by Roy's son and (10) grief the rest of heir took over in the sea to contain (3) that would be used to fight off invaders. After the war, the soldiers left these platforms and they were forgotten - until 1967. In that year, a British man, Roy Bates, one of the platforms and announced he had started his own country, b. poor himself by his own country. During World War II, the UK built a number of artificial platforms made a name for weapons who believed they had the (5) the people on the island (his family), (7) to the platform. orders In 1968, a court decided that the UK had no power over Sealand. Just like other places with the that the platform was in international waters. of a country, Sealand, has its own stamps, coins, and passports. It is controlled 'Prince' Michael, and is home to a large Internet business. in 11-15

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英語 高校生

教えて下さると嬉しいです。。涙

Circle the correct answer for each question. A. likely to be jealous of someone 1. You are more 2. Which do many people decorate at Christmas time? 3. Which are people a. rich a. a feast a. spending money b. receiving awards a. an empire b. a rifle a. an insect b. water a. help it b. ruin it a. excited b. confused a. a contract b. a feast a. a recruit b. a contract a. being punished b. getting a reward B. Complete the paragraph with items from the box. Two items are extra. 4. Which of these is a weapon? 5. Which of these flows? more accustomed to? 6. What would profit do for a business? 7. Which would people rather be? 8. Which would 9. Which would you sign? 10. Which would few people enjoy? discovered resembled you invite friends to share with you? called Sealand. establishing rights faced status grief the rest of Many people change countries during their life, but one man has (1) (2) heir took over (9) by Roy's son and (10) This surprised people in the UK, who believed they had the (5) . Bates and (6) to leave the platform. However, Roy (8) - b. poor in the sea to contain (3) that would be used to fight off invaders. After the war, the soldiers left these platforms and they were forgotten - until 1967. In that year, a British man, Roy Bates, one of the platforms and announced he had started his own country, b. a tree himself by his own country. During World War II, the UK built a number of artificial platforms the people on the island (his family), (7) - - made a name for weapons to the platform. orders In 1968, a court decided that the UK had no power over Sealand. Just like other places with the that the platform was in international waters. of a country, Sealand, has its own stamps, coins, and passports. It is controlled 'Prince' Michael, and is home to a large Internet business. im 11 - 15

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物理 高校生

電磁誘導がわからないです。 疑問①(3)で電流×eは仕事になる理由が分かりません。 ②(4)で何故少し上昇した後に落下を初めてしばらくすると一定の速さになるのか分からないです。

170 第4編・電気と磁気 a R b S₁ 291. 磁場の中での導体棒の運動図のように, 内部抵抗の 無視できる起電力Eの電池, 抵抗値Rの抵抗およびスイッチから なる回路がある。回路内のabとcd は間隔だけ離れて鉛直方 向に立てられ,それに接した長さ 質量mの導体棒Aが水平に 配置されている。Aは鉛直方向のみに, ab, cd に接しながらな めらかに動くようになっている。 また, 磁束密度Bの一様な磁場 (磁界)が回路に垂直に、紙面の裏から表の向きに加えられている。 重力加速度の大きさをg とし 回路内の導体の抵抗は無視する。 (1) Aを支えたままスイッチを S, に入れた。 その後, 支えをとると, Aは鉛直上向きへ BO E S2 鉛直 上向き d 動きだした。 速さがvのときの電流 I を求めよ。 (2) しばらくすると一定の速さになった。 この速さを求めよ。 (3) このとき,単位時間に、電池がする仕事 W, 抵抗で発生するジュール熱 Q, Aが得 る重力による位置エネルギーUを,それぞれ求めよ。 また, W, Q, U の間に成りた つ関係式を求めよ。 (4) Aが一定の速さになった後, スイッチを2に入れたところ, Aは少し上昇した後に 落下を始め, しばらくすると一定の速さになった。この速さを求めよ。 -285

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数学 高校生

写真の問題の赤線部についてですが、なぜn≧1と書く必要があるのでしょうか? その上の行でΣとCをすでに使っていますが、ΣとCのnの部分は定義から、n≧1だから、赤線部の前にn≧1という条件はすでに考慮してるのではないのでしょうか?解説おねがいします。

基礎問 P 44 はさみうちの原理(I) 次の問いに答えよ. (1) すべての自然数nに対して,2"> n を示せ. AOAO k-1 (2) 数列の和 S. = 2 (1) anで表せ△〇〇〇 k=1 (3) lim Sm を求めよ. △△△△ n→∞ |精講 (1) 考え方は2つあります。 I. (整数)” を整式につなげたいとき, 2項定理を考えます. PROCE (数学ⅡI・B4 ⅡI. 自然数に関する命題の証明は帰納法 (数学ⅡI・B 136 Fet (2) Σ計算では重要なタイプです. (数学ⅡB 120 S=Σ(kの1次式) k+c (r≠1) は S-S を計算します. (3) 極限が直接求めにくいとき, 「はさみうちの原理」という考え方を用います. bn≦an≦en のとき limb=limcn = α ならば liman=α n→ 00 n→∞ n→∞ この考え方を使う問題は,ほとんどの場合,設問の文章にある特徴がありま す. (ポイント) どういう意味? 解答 (1) (解I)(2項定理を使って示す方法) n (x+1)=2nCkck に x=1 を代入すると k=0 2"=nCo+nC1+nC2+..+nCn ¹) n=1 F²³5, 2²nCo+nC₁=1+n>newhere 2">n ( 解ⅡI) (数学的帰納法を使って示す方法 ) 2"> n (i) n=1のとき 左辺=2,右辺=1 だから, ①は成りたつ

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