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理科 中学生

大問3の(5)がわかりません。解説も含めてどなたかお願いします

3 回路に関する次の問いに答えよ。ただし,水1gの温度を1℃上昇させるために必要なエネルギーを4.2」と し,抵抗で発生した熱はすべて水の温度上昇に使われるものとする。 (1)電源装置,電流計, 電圧計,いくつかの抵抗を用意し、 右の図のような回路をつく った。抵抗にかかる電圧をはかるためには, 電圧計を右の図のアイのどちらにつな げばよいか。 (2)図のAB間に次の① ~ ④ のいずれかをつなぎ, 電圧計の値が20Vを示すように電源 装置の電圧を設定した。電流計の値はそれぞれ何Aになるか。 小数第1位まで答えよ。 必要があれば小数第2位を四捨五入すること。 ① 40Ωの抵抗 (2) 40Ωと10Ωの抵抗を直列につないだもの ③ 40Ωと10Ωの抵抗を並列につないだもの 〈函館ラ・サール〉 B ④ 40Ωと10Ωの抵抗を並列につないだものに32Ωの抵抗を直列につないだもの (3)(2)④の10Ωの抵抗で消費される電力は何Wか。 (4)(2)の①~③の抵抗を,それぞれ100gの水が入った断熱容器に入れた。電圧計の値が20Vを示すように電 源装置の電圧を設定し,電流を63秒間流した場合、水の温度が最も上昇したのはどの抵抗を入れた容器か。 ①~③の記号で答えよ。また,その抵抗を入れた容器では水の温度は何℃上昇するか。小数第1位まで答え よ。必要があれば小数第2位を四捨五入すること。 記号 温度 (5)40Ωの抵抗と10Ωの抵抗をそれぞれN個ずつ用意し,合計2N個の抵抗をすべて直列につないだR」と, すべて並列につないだR2をつくった。 次に, 100gの水が入った断熱容器を2つ用意し, 一方にはR」を, も う一方にはR2を入れた。 電圧計の値が20Vを示すように電源装置の電圧を設定し,電流を63秒間流したと ころ,R2を入れた容器の水温の上昇幅がR」 を入れた容器の水温の上昇幅の25倍になった。 Nの値を整数で 答えよ。 4 図1のように机の上にコイルと導線PQを置く。 コイルと検流計を接 続し、机の上方からコイルの中心に向けて磁石のN極を近づけると,検 流計の指針は左に振れた。 図 1 〈大阪教育大池田〉 コイル (1) コイルに磁石を近づけたときに,コイルに電流が流れる現象を何と いうか。 その名称を書け。 検流計 本日 (2)記述磁石のS極をコイルの中心から上方に遠ざけると,検流計の指針はどうなるか。簡単に書け。 (3) PからQの向きに流れる電流を正QからPの向きに流れる電流を 負として、導線PQに流れる電流を図2のグラフのように変化させた。 図2 電流 24-

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英語 中学生

問4の並び替えはどのように考えて解けばいいのですか?

3 次は、高校生のHayato (男性) が書いた文章です。 これを読んで, 間 1~ 問6に答えなさい。 *印の ついている語句には、本文のあとに〔注〕があります。(34点) I love bicycles. I've been using my bicycle since I was a junior high school student. One morning, however, I got scared on my way to school. A car passed me really fast. It almost touched my bicycle. There are only a few *bicycle lanes in my town, and I think some of those lanes are too narrow for a bicycle to use safely. I wanted to make our streets safer for cyclists, and then I read about "Copenhagen, Denmark in a bicycle "magazine. It's Aas one of the most *bicycle-friendly cities in the world. I learned more about the city on the Internet and thought it's really a wonderful city for cyclists. I'd like to write about it. In Denmark. 90% of the people have a bicycle, and in Copenhagen, 49% of the workers and students go to work or school by bicycle (27 % go by car, 18% by bus or train, and 6% on foot). Many streets in the city have bicycle lanes and bicycle traffic lights, and there is even a bicycle bridge named "The Bicycle "Snake." I was "envious of the cyclists in Copenhagen because the city is bicycle-friendly in every way. You can ride a bicycle at 20 km/h without B at red lights even when the traffic is busy, and you can bring your bicycle on trains and buses. In the 2019 ranking of "Bicycle-friendly Cities," Copenhagen was No. 1 and Tokyo was No. 16. ② A lot of people were using cars in Copenhagen, too, but around 1980, the city started making better roads and rules for bicycles, and the number of bicycle users started increasing. Around 2017, the number of bicycle users in Copenhagen became almost the same as the number of car users. I was also surprised to see that the number of bicycle accidents in Copenhagen was "lower than in other large cities. I think it's because the roads (cyclists for safe/follow/ and/ are cyclists the traffic rules. In many Japanese road safety classes, children are taught that roads are dangerous and sometimes shown shocking scenes of traffic accidents, and they learn that they must follow traffic rules when they ride a bicycle. But in Denmark. children play games in their classes. They can have fun when they learn traffic rules. Now there is a movement in Japan that gives children road safety classes in this way. Bicycles are cheaper than cars and healthier. They're also friendlier to the environment. The United Nations expects that about 70% of the people in the world will live in big cities by 2050. Such a large number of people will cause some problems, and more traffic is one of them. Copenhagen is a very good role model for Sustainable cities and communities" which is one of the U.N.'s "Sustainable Development Goals. I think Copenhagen's ideas to increase the number of bicycle users are wonderful because people there don't have to stop doing anything. They choose bicycles because the city is designed in a way that using a bicycle is more convenient than using a car, bus. or train. However, after the number of bicycle users increased, more parking spaces are needed there. (3 To make a bicycle-friendly city, just making more bicycle lanes isn't enough. We must think about the future of our cities. Denmark has made a lot of great plans and has more exciting plans for the future. For example, it's going to build a "bicycle" "superhighway" between cities and other areas by around 2045. I definitely want to ride a bicycle on it some day! 〔注〕 be cared おびえて こわがって bicycle lane 自転車専用の車線. レーン cyclist ...... 自転車乗りの人、サイクリスト pass…………〜を追いこす。 通り過ぎる narrow ・・・・・・幅が狭い Copenhagen コペンハーゲン (Denmark 「デンマーク」の首都) magazine 雑誌 on foot... 徒歩で bicycle-friendly... 自転車にやさしい traffic light...信号 (traffic は 「交通 (量)」)

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