【正文】 8104N。5A26．6104Pa。180。拉90%=240牛 拉力F的功率：P=FV11拉=F180。=5W答案：10 N；5 W16.(1)2 m/s(2)480 J(3)120 W1⑴⑵2103Pa1⑴105N⑵105Pa1⑴⑵102m3% 22．解：拉力F的大小可由下式求得∵η=W有物W=fSLFS拉∴F=fS拉180。s丙=4020J＝800 JPW甲160W400甲=t=＝800w，P乙乙=t=W＝50W，PW800丙=丙甲t=W＝200W乙8丙415．解析：如圖所示，是一個(gè)動(dòng)滑輪，物體在做勻速運(yùn)動(dòng)．彈簧秤示數(shù)為5 N．F＝2F彈=2 5 N＝10 N因?yàn)槲矬w在水平方向1m／s的速度做勻速運(yùn)動(dòng)，所以F拉G在水平方向上以0．5 m／s的速度做勻速運(yùn)動(dòng)．P＝Wt=Fs甲＝802J＝160 J，W乙=F乙104t得：t=P=180。S′＝1．5104Pa 5102m2＝750 N．因?yàn)镚＝F，所以罪犯體重為750 N． N下沉（1）104 N（2）104 N（3） m3（4） m3 N（1）1100 N（2） m 11． 200N，(2)η＝80％．12． W1041J=6104有＝Gh＝6JW．51046104)J=1．5104總=W總W有=(7J(2)s＝3h＝31m=3m，F(xiàn)=W總s=180。30176。C180。103J/kg℃)0．25 kg(56020)℃＝62．1103J鋼刀放出的熱全部被水吸收Q吸=c水m水Δt水ΔtQ吸水=c=180。104m＝15m／s． 2t240min2400s3．解：以隊(duì)伍為參照物，則列車的速度為：v＝54 km／h5 m／s=15 m／s5 m／s＝10m／s．要穿過隊(duì)伍．則列車要經(jīng)過的路程為：s=150 m+130 m＝280 m．所以，列車要穿過隊(duì)伍所用時(shí)間為：t＝s/v=280 m247。第五篇：九年級上冊物理人教版練習(xí)冊答案九年級上冊物理人教版練習(xí)冊答案 kg：，根據(jù)v=st可知：1s=v1t1=36km/h180。（5）略（6）圍繞“物質(zhì)生活優(yōu)裕了，仍然需要憂患意識”或“因有憂患得以生存，因沉迷安樂而衰亡”來回答。（1）法家拂士 敵國外患（2）都是在經(jīng)歷了一番艱難困苦之后，成就了不平凡的事業(yè)。③眾人拾柴火焰高④團(tuán)結(jié)就是力量⑤人心齊，泰山移。（3）這樣之后人們才會明白憂患使人生存發(fā)展，而安逸享樂使人萎靡死亡。去：離開。m annoyed because I just missed the 39。s home after 6 is necessary for him to take an umbrella with is possible for me to reach the railway station in is impossible for her to reach the dentist by/at is difficult for him to plete his homework in half an is convenient for him to pick up the is necessary for her to take medicine three times a is OK for them to stay at the beach for several is important for her to practise swimming as often as errors was stupid enough not to take my parents39。第一篇：(2012秋)九年級練習(xí)冊答案（2011秋）初三牛津練習(xí)冊答案（第 02單元）(閱讀時(shí)請放大至130140%效果更佳)Chapter 2 Vocabulary A B on top of the world 8 set LanguageCommon errors is hard for him to help 39。s convenient fοr her to e is difficult for David to finish his homework before 9 is important for you to remember the time of the is fine for Lily to e to her teacher39。 was old enough to go to enough to beat everyone else enough not to go to bed late enough to study till enough to get up at enough to study for two more hours enough to fall asleep during/in the test enough not to check the answers carefully enough to learn from our mistakes Common errors was nice of him to remember my was generous of Linda to buy such a good book for was nice of him to send some beautiful flowers to me on my was kind of her to lend her MP3 player to was right of him to report the two thieves to the was silly of meto sell my old puter to Molly at a very low errors39。s relaxing to stay at home and read was interested in the TV E for you to stay out of Mr Yu to lend enough to help for her to write enough to see of him to shout enough not to cross enough to reach enough to read of you to giveListening and Speaking A B1 1 F 2 F 3 F 4 F 5 F B2 5 1 2 6 3 4ReadingA l F 2 F 3 F 4T 5 F 6T B their think women with long blonde hair are more attractive and less chose short hair to show they were strong and chose short hairstyles to show that they were modern，successful and should make sure the hairstyle expresses their true (possible answers)A badminton my ankle to hospital for one week BDear KimI am writing to tell you that I cannot make the appointment am still in Beijing now and my flight to Shenzhen has been delayed because of bad weather，so I have to stay for one more am sorry to inform