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英語 高校生

下から5行目のit would~の文構造がわからないです。back upはどのような働きをしているのでしょうか。 教えて頂けるとありがたいです。

A Makeover for Hoover Dam Hydropower has attracted increasing attention in recent years as a renewable type of clean energy. As long as a suitable water source is available, hydropower facilities are usually good investments, producing energy in a manner that generates far less air pollution and CO2 emissions than fossil fuels do. The most common way to generate hydropower is to trap water at a high elevation behind a dam so it can be released and used to spin turbines below, which, in turn, power electricity-producing generators. However, hydropower has its drawbacks. Droughts and increased water consumption have reduced the flow of many rivers. As rivers become shallower, the necessary volume of water for electricity difficult to maintain, and power supply and generation is dependability are negatively impacted. more Variability in water levels has particularly affected Hoover Dam, a mega-scale hydropower facility in the US state of Nevada. Built in the 1930s at enormous expense to control the frequently flooding Colorado River and maintain a water supply for farmland irrigation, the dam's hydropower capabilities were seen as a way to recover some of the costs of its construction over the long term. The dam's electricity-generating capacity, however, was challenged from the start by seasonal variability in water flow, and in recent years has been greatly reduced by droughts. Combining hydropower with other alternative energy sources, though, may offer a solution. Solar and wind plants can produce enormous amounts of electricity, but one serious downside is that the energy they produce is not available when there is little sun or wind. While conventional batteries can help with this issue, storing such tremendous volumes of electricity has long been a challenge. A recently proposed system for Hoover Dam could provide an answer, though. The plan suggests building a new pumping station that would be powered by both wind and solar. It would push water from the river back up to Hoover Dam, refilling the lake behind it. The water could be released anytime to power the dam's generators in order to reliably meet demand for electricity. Kelly Sanders, an engineering professor at the University of Southern California, is enthusiastic about the storage plan, saying, "We by the p replace fo solat als are st ons to the What is 1 Inst inves 2 WE dams 3 A neg sys 1 en

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物理 高校生

問3で私の答えが5番になったのですが答えは2で、どこが違ってきているか分かりません。

- Cosy) 9 0 分 直後での運動量保 **第18問 次の文章を読み、下の問い (問1~3)に答えよ。 (配点 12 【10分 図1のように水平な床の上に半頂角0の円錐をその軸が鉛直になるように固定 した。円錐の頂点から質量mの小球が長さの軽い糸でつるされており、円錐 と接しながら角速度で等速円運動をしている。 糸は伸び縮みせず。円錐面はなめ らかである。ただし、重力加速度の大きさをgとする。 とする 0 問 等速円運動の周期はいくらか。 正しいものを、次の①~⑥のうちから一 つ選べ。 T= 1 会 20 mgsin+lucos²8) O' m (gcose + lu'sin¹0) 2x W w² (r-mlsing) = gross and rw²³-mew singsing cos 問2 小球が糸から受ける張力の大きさSはいくらか。 正しいものを次の①~8 のうちから一つ選べ。 S 2 17 W 2x 2 m (gsinf-lo cos³0) mr W=gsind cost + me ursing 4mgcost-la'sin³0) mairt (gos + sin() W² = [sing wire w f =mrw² (0) (050)-1) b = 2,415 M Tsint F Tco₂0 mg J 20 I (groso + lu² sino) cost = g U₁² 11 groso sino 問3 をいろいろ変えて小球を等速円運動させるとき、小球にはたらく垂直抗力 の大きさは図2のように変化した。 図2のc)はいくらか。 正しいものを、下 の①⑤のうちから一つ選べ。 03 m = mg sing w²=lgsing 〒53 0 mr 4 masin mg (050+ lw²siño) = [ 9 V Isin __w² T mut sing gcos T mg sine + N mg coso 2 QF mg 1030 Im CO₂O mg Burg mycose + ml wsing T T my co me sinfu = ((stein² ou ² ) 9 Icos my cosp 図2 Ex mg = m + cos w² g r como e COD w² mgsing N mesingumasing macoso I + me sinow sint ex=lsing gsin 1 Tsing BSAJN + == T-mg cose my 00 Aug Tcose + Nsin0 = mg) Ttanf Too 30 My he ca = 3 mrw² mg _ru tand: g w² wid. ₂N

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英語 高校生

(4)の答えがthe problemでしたがsolving the problemではダメでしょうか?

humans. "We were able to identify one of the many molecular features that likely shape behavior," she adds. ** hol boquete es Though the origins of the dog/human partnership remain unknown, it's becoming increasingly clear that each species has changed (during our long years header The physical differences between a basset hound and wolf are obvious, but dogs have also changed in ways that are more than skin (or fur) deep. One recent study shows how by bonding with us and learning to work ogether with humans, dogs may have actually become worse at working together Their pack lifestyle and mentality appear to be reduced and are far as a species. less prevalent even in wild dogs than in wolves. But, Yale's Laurie Santos says, dogs may have compensated in other interesting ways. They've learned to use humans to solve problems. "Several researchers have presented dogs and wolves with an impossible problem (e.g., a puzzle box that can't be opened or a pulling tool that stops working) and have asked how these different species react," Santos explains. Researchers have found that wolves try lots of different trial and error tactics to solve the problem - they get at it physically. But at the first sign of trouble, dogs do something different. They look back to their human companion for help. This work hints that dogs may have lost some of their physical problem-solving abilities in favor of more social strategies, ones that rely on the unique sort of cooperation

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英語 高校生

when poor environmental health and reduced quality of life are actually good for the economy の理由が 低下した自然サービスと戦うために必要な活動や製品がGDPを増大させるから な... 続きを読む

第3・4段落 1So how do we reconcile our economy with ecology? The Earth provides us with essential natural services like air and water purification and climate stability, but these aren't part of our economy because we've always assumed such things are free. 3But natural services are only free when the ecosystems that maintain them are healthy. 4Today, with our growing population and increasing demands on ecosystems, we're degrading them more and more. Unfortunately, remedial activities and products like air filters, bottled water, eye drops and other things we need to combat degraded services all add to the GDP, which economists call growth. Something is terribly wrong with our economic system when poor environmental health and reduced quality of life are actually good for the economy! 「それでは,私たちはどのようにして経済と環境の折り合いをつけるのだろうか。 地球は空 気や水の浄化、気候の安定性といった必要不可欠な自然のサービスを提供してくれるが,私た ちはこれまでずっとそういうものは無料だと思い込んでいたので,それらは経済の一部とはな っていない。 しかし、自然のサービスが無料なのは, それを維持する生態系が健全なときだけなのであ る。 4今日,人口が増加し生態系への負担が高まるにつれ,私たちは生態系をますます傷つけて いる。 5残念なことに, 環境改善のための活動や製品,たとえばエアフィルター, ボトル入りの 水,目薬や質が低下したサービスに対処するために私たちが必要とするその他のものはすべ て GDPを増加させるが, それを経済学者は成長と呼ぶ。 環境が不健全になり、生活の質が低 下していることが実は経済にとってよいことなら、私たちの経済システムは何かがひどく間違 っているのである。 □ecology 「環境,生態」 2□essential 「必要不可欠な」 □ stability 「安定性」 30ecosystem 「生態系」 4 demand on A 「A への要求, 負担」 □ purification 「浄化」 □ climate 「気候」 □ free 「無料の」 | degrade 「を悪化させる, の質を低下させる」 99

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