【題目】如圖所示，A、B兩球質(zhì)量相等，光滑斜面的傾角為
，圖甲中，A、B兩球用輕彈簧相連，圖乙中A、B兩球用輕質(zhì)桿相連，系統(tǒng)靜止時，擋板C與斜面垂直，彈簧、輕桿均與斜面平行，則在突然撤去擋板的瞬間有（ ）
A．兩圖中兩球的加速度均為
B．兩圖中A球的加速度均為零
C．圖乙中輕桿的作用力一定不為零
D．圖甲中B球的加速度是圖乙中B球加速度的2倍
科目：高中地理 來源： 題型：
【題目】A
In 1995, Oseola McCarty gave a present of $ 150,000 to the University of Southern Mississippi. She wanted to help poor students. It was a very generous thing to do. But her friends and neighbors were surprised. McCarty was a good woman. She went to church. She was always friendly and helpful. But everyone in her town knew that McCarty was not rich. In fact, she was poor.
How did a poor 86-year-old woman have so much money? Oseola McCarty was born in 1908 in Hattiesburg, Mississippi. She had to leave school when she was eight years old to help her family. She took a job washing clothes. She earned only a few dollars a day. Oseola washed the clothes by hand. Then she hung the clothes to dry. She did this for nearly 80 years. In the 1960s’ she bought an automatic washer and dryer. But she gave them away. She did not think they got the clothes clean enough! At that time, many people started to buy their own washers and dryers. McCarty did not have much work, so she started to iron clothes instead.
McCarty never married or had children. Her life was very simple. She went to work and to church. She read her Bible. She had a black-and-white television. But she did not watch it very much. It had only one channel.
McCarty saved money all her life and eventually had about $250,000.When she was 86, a lawyer helped her make a will. She left money to the church, her relatives, and the university. McCarty just wanted to help others. She did not think she was a special person. But then people found out about her present to the university. She received many honors(榮譽(yù)). She even flew in an airplane for the first time! Oseola McCarty died in 1999.She was a shy and ordinary woman who became famous.
【1】Oseola McCarty gave $150,000 to the University of Southern Mississippi __________.
A. to help the poor students
B. to surprise her friends and neighbors
C. to show her generosity
D. to be a good and rich woman
【2】From the story we know ___________.
A. McCarty was born in a poor family near the University of Southern Mississippi
B. everyone was surprised because they thought McCarty had no education
C. washers and dryers brought a change in McCarty’s life
D. McCarty gave half of her money to the church and her relatives.
【3】 Which of the following is true?
A. McCarty had to work to help her family after school every day.
B. McCarty learned to read the Bible by herself in the school.
C. McCarty made one third of her money by washing and ironing clothes.
D. McCarty did not have her own family because she had no husband or children.
【4】 From which of the following can we tell McCarty lived a simple life?
A. She worked hard all her life.
B. She didn’t think she was special.
C. She didn’t have many interests.
D. She had a TV set with many channels.
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【題目】目前有些居民區(qū)內(nèi)樓道燈的控制，使用的是一種延時開關(guān)。該延時開關(guān)的簡化原理如圖所示。圖中D是紅色發(fā)光二極管（只要有很小的電流通過就能使其發(fā)出紅色亮光），R為限流電阻，K為按鈕式開關(guān)，虛線框內(nèi)S表示延時開關(guān)電路，當(dāng)按下K接通電路瞬間，延時開關(guān)觸發(fā)，相當(dāng)于S閉合，這時釋放K后，延時開關(guān)S約在1 min后斷開，電燈熄滅。根據(jù)上述信息和原理圖，我們可推斷：
按鈕開關(guān)K按下前，發(fā)光二極管是________（填“發(fā)光的”或“熄滅的”），按鈕開關(guān)K按下再釋放后，電燈L發(fā)光持續(xù)時間約________min。這一過程中發(fā)光二極管是________。限流電阻R的阻值和燈絲電阻RL相比，應(yīng)滿足R________RL的條件。
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【題目】如圖所示，可看做質(zhì)點的兩物塊A，B，質(zhì)量分別為2m，m。A放在光滑水平桌面上，一不可伸長的柔軟輕繩跨過光滑輕質(zhì)定滑輪，兩端分別與A、B相連接，A和滑輪間的輕繩與桌面平行。現(xiàn)將A從靜止釋放，當(dāng)B落地時，A還在桌面上。不計空氣阻力，重力加速度為g。求：
（1）B落地前的加速度a的大小；
（2）B落地前滑輪對輪軸的壓力F大小。
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【題目】右圖所示的實驗裝置驗證m1、m2組成的系統(tǒng)機(jī)械能守恒．m2從高處由靜止開始下落，m1上拖著的紙帶打出一系列的點，對紙帶上的點跡進(jìn)行測量，即可驗證機(jī)械能守恒定律．如圖給出的是實驗中獲取的一條紙帶：0是打下的第一個點，每相鄰兩計數(shù)點間還有4個點（圖中未標(biāo)出），計數(shù)點間的距離如圖所示．已知m1＝50 g、m2＝150 g，則（結(jié)果均保留兩位有效數(shù)字）
（1）在紙帶上打下計數(shù)點5時的速度v＝______m/s；
（2）在打下第“0”到打下第“5”點的過程中系統(tǒng)動能的增量ΔEk＝________ J，系統(tǒng)勢能的減少量ΔEp＝______J；（取當(dāng)?shù)氐闹亓铀俣萭＝10 m/s2）
（3）若某同學(xué)作出
v2－h(huán)圖象如圖所示，則當(dāng)?shù)氐闹亓铀俣萭＝________m/s2.
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【題目】化學(xué)興趣小組為探究SO2的性質(zhì)，按下圖所示裝置進(jìn)行實驗。(已知：Na2SO3+H2SO4===Na2SO4+SO2↑+H2O)
請回答下列問題：
(1)裝置A中盛放濃硫酸和亞硫酸鈉的儀器名稱分別是________、________。
(2)反應(yīng)后，裝置B中發(fā)生的現(xiàn)象是_________________________________；反應(yīng)的離子方程式為______________________________；裝置C中的現(xiàn)象是___________________________，表現(xiàn)了SO2的________；裝置D中現(xiàn)象是_____________________________________________，發(fā)生反應(yīng)的化學(xué)方程式為_________________________________________。
(3)裝置E的目的是探究SO2與品紅作用的可逆性，請寫出實驗操作及現(xiàn)象_________________________。
(4)F裝置的作用是________________________，漏斗的作用是___________________________。
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【題目】如圖所示是一種延時開關(guān)，當(dāng)S1閉合時，電磁鐵F將銜鐵D吸下，將C線路接通。當(dāng)S1斷開時，由于電磁感應(yīng)作用，D將延遲一段時間才被釋放。則下列說法中正確的是（ ）
A．由于A線圈的電磁感應(yīng)作用，才產(chǎn)生延時釋放D的作用
B．由于B線圈的電磁感應(yīng)作用，才產(chǎn)生延時釋放D的作用
C．如果斷開B線圈的開關(guān)S2，無延時作用
D．如果斷開B線圈的開關(guān)S2，延時將變長
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【題目】鉛蓄電池的工作原理為Pb＋PbO2＋2H2SO4=2PbSO4＋2H2O。研讀下圖，下列判斷不正確的是( )
A．K閉合時，d電極反應(yīng)式：PbSO4＋2H2O－2e－=PbO2＋4H＋＋SO42－
B．當(dāng)電路中轉(zhuǎn)移0.2 mol電子時，Ⅰ中消耗的H2SO4為0.2 mol
C．K閉合時，Ⅱ中SO42－向c電極遷移
D．K閉合一段時間后，Ⅱ可單獨作為原電池，d電極為正極
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