第二次作业(习题及答案)
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第四章 第二次作业及答案1. 考虑地球为自转椭球模型,请推导地面返回坐标系及弹道坐标系(半速度坐标系)下航天器无动力再入返回质心动力学方程和运动学方程,以及绕质心旋转动力学和运动学方程。
解答:(1)地面返回坐标系:原点位于返回初始时刻地心矢径与地表的交点处,ox 轴位于当地水平面内指向着陆点,oy 垂直于当地水平面向上为正,oz 轴形成右手坐标系。
地面返回坐标系下的动力学方程:与发射坐标系下的动力学方程形式相同,令推力为0即可得到。
(2)弹道(航迹,半速度)坐标系定义:原点位于火箭质心,2ox 轴与速度矢量重合,2oy 轴位于包含速度矢量的当地铅垂平面内,并垂直于2ox 轴向上为正,2oz 轴形成右手坐标系。
由于弹道坐标系是动坐标系,不仅相对于惯性坐标系是动系,相对于地面返回坐标系也是动系,在地面坐标系下的动力学方程可以写为:惯性系下:22222()=F=++m e e e d m m m m t dt tδδδδ=+⨯+⨯⨯r r rωωωr P R g地面系下:22=++m -2-()e e e m m m t tδδδδ⨯⨯⨯r rP R g ωωωr弹道系下:22=()=++m -2-()t e e e m m m m m t t t tδδδδδδδδ'=+⨯⨯⨯⨯'r v v rωv P R g ωωωr 式中,tδδ''v 表示速度矢量在弹道坐标系的导数,t ω表示弹道坐标系相对于地面坐标系的旋转角速度,将上式矢量在弹道坐标系分解得到:速度矢量00v ⎡⎤⎢⎥=⎢⎥⎢⎥⎣⎦v ,角速度矢量=tx t ty tz ⎡⎤⎢⎥⎢⎥⎢⎥⎣⎦ωωωω 00cos 0sin 00sin =+=()001000sin 0cos 0cos t y L σσσθσσσσθσσθσθ⎡⎤--⎡⎤⎡⎤⎡⎤⎡⎤⎡⎤⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥+=+=⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎣⎦⎣⎦⎣⎦⎣⎦⎣⎦⎣⎦ωθσ sin 0cos 0=0cos 0sin 0cos cos 0sin 00t v v v v σθσθσσσθσθσθσθσσθσ⎡⎤⎡⎤--⎡⎤⎡⎤⎡⎤⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⨯⨯==⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥---⎣⎦⎣⎦⎣⎦⎣⎦⎣⎦ωv 等式左边:()=cos t vm v tv δσθδσ⎡⎤'⎢⎥+⨯⎢⎥'⎢⎥-⎣⎦vωv 等式右边将所有力转换到弹道坐标系下,如果不方便直接转换,可以先转到地面系,然后再转到弹道系。
P84,习题4-21、用0.1000mol/L HNO 3溶液滴定20mL 0.1000mol/L NaOH 溶液时,化学计量点时pH 为多少?化学计量点附近的突跃范围为多少?应选用何种指示剂指示终点? 解:有关反应为:O H NaNO NaOH HNO 233+=+化学计量点时产物为NaNO 3为中性,则pH=7.0。
1)当加入的HNO 3的体积为19.98mL ,即滴定度为99.9%时,溶液中的酸度主要来源于过量的NaOH ,则:70.8,30.5,100.598.391000.0)98.1900.20(][5==⨯=⨯-=--pH pOH OH2)当加入的HNO 3的体积为20.02mL ,即滴定度为100.1%时,溶液中的酸度主要来源于过量的HNO 3,则:30.5,100.502.401000.0)00.2002.20(][5=⨯=⨯-=-+pH H故化学计量点附近的突跃范围为:pH=5.30—8.70。
可选择中性红为指示剂。
2、某弱酸的pK a =9.21,现有其共轭碱NaA 溶液20.00mL 浓度为0.1000mol/L ,当用0.1000 mol/L HCl 溶液滴定时,化学计量点时pH 为多少?化学计量点附近的突跃范围为多少?应选用何种指示剂指示终点? 解:有关反应为:HA NaCl NaA HCl +=+化学计量点时产物为HA 弱酸,其浓度为:21.910,/05000.0-==a HA K L mol c , 由于:10510/100.5/,10100.521.9221.11>⨯=>⨯=---a HA w a HA K c K K c 则可用最简式计算:26.5,100500.010][26.521.9==⨯==--+pH c K H HA a可选择甲基红为指示剂。
当滴定度为99.9%时,即加入的HCl 体积为19.98mL 时,溶液的pH 值由过量的NaA 与生成的HA 组成的缓冲体系来计算。
第2次作业一、单项选择题(本大题共50分,共25小题,每小题2分)1.C++程序屮,数据的两种表现形式是()。
A.常最和变最B.常量和矢量C.变量和矢量D.矢量和标量2.C++程序中,定义函数时()。
A.可以嵌套定义B.可以不指定函数名C.不能嵌套定义D.可以不指定返冋值类型3.C++程序屮,主函数的常用返回整型数据的形式,类型名是()。
A.intB.INTC.integerD.Tnt4.C++程序中,用于实现数据输入的是()。
A.输入流对象cin和提取运算符>>B.输入流对象cin和插入运算符《C.输入流对彖cout和提取运算符>>D.输入流对象cout和插入运算符〈〈5.C++程序屮,定义引用变量时,()。
A.使用的运算符是*B.使用的运算符是()C.使用的运算符是&D.使用的运算符是[]6•下列关于函数的说法屮,不正确的是()。
A.在不同函数屮可以使用相同的名字命名变量B.形式参数是局部变量C.在函数内部定义变量的作用域在本函数中D.在一个函数内的复合语句屮定义变量的作用域也是整个函数7. C++程序的函数调用屮,使用数值参数传递吋,()oA.能够在被调函数屮通过形参修改实参B.实参和对应的形参数据类型可以不一致C.形参不能够从实参获取数值D.不能在被调函数屮通过形参修改实参&在C++程序小,注释的书写方法除了/**/这种形式外,述可以使用的形式是()OA.字符序列〉”B.\0〈字符序列>\0C.〃v字符序列〉D.\\〈字符序列〉9.C++语言中,定义一个文件流对象的正确语句形式是()。
A.void *sp;B.fstream sp;C.FILE &sp;D.filestream *sp;10.对于字符常量'B',与其对应的转义字符书写形式是()oA.B.'\x42'C.'\x41'D.'\A,11.C++程序的函数调用中,使用数组参数传递时,()。
(第二次作业)2-1 某办公楼工程地质勘察中取原状土做试验,用体积为1003cm 的环刀取样试验,用天平测得环刀加湿土的质量为245.00g ,环刀质量为55.00g ,烘干后土样质量为170.00g ,土粒比重为2.70。
计算此土样的天然密度、干密度、饱和密度、天然含水率、孔隙比、孔隙率以及饱和度,并比较各种密度的大小。
解:已知:V=100 cm 3;M=245-55=190g ;M s =170g ;土粒比重Gs=M s /V s =2.70; M w = M - Ms=186-170=16g ,ρw=1 g/cm 3;所以V w =16cm 3; 土粒比重G s =M s /V s =2.70;所以V s = M s /2.70=62.96cm 3; V=100 cm 3;Vs=62.96cm 3;Vw=16cm 3;所以V v =V-V s =100-62.96=37.04cm 3;V a =V v -V w =37.04-16=21.04 cm 3; 因此:天然密度Vm=ρ=190/100=1.90 g/cm 3; 干密度/ds m Vρ= =170/100=1.70 g/cm 3;饱和密度()/sat s v w m V V ρρ=+=(16+170+21.04×1)/100=2.07 g/cm 3;天然含水率%42.9%10017016%100=⨯=⨯=s w m m w 孔隙比/v s e V V == 37.04/62.96=0.588孔隙率()/100v n V V =⨯%=V v/V=37.04/100=37.04%饱和度()/100rw v S V V =⨯%=16/37.04=43.2%综上所述:ρsat >ρ>ρd2-3某住宅地基土的试验中,已测得土的干密度d ρ=1.643/cm g ,含水率w =21.3﹪,土粒比重S G =2.65。
计算土的e 、n 和r S 。
[2023春期]国开河南电大专科《公务员制度讲座》
形考任务
第二次作业练习试题及答案
1.下列选项中,属于公务员的是
A.作家协会副主席
B.教育部直属高校校长
C.公安派出所所长
D.城市社区居委会主任
[答案]C
2.领导成员辞去公职的审批期限是
A.60天
B.15天
C.30天
D.45天
[答案]A
3.下列既是公务员权利,又是公务员义务的是
A.批评建议
B.依法辞职
C.参加培训
D.获得报酬
[答案]C
4.非领导职务中的巡视员相当于
A.正部级
B.正处级
C.正厅级
D.副厅级
[答案]C
5.政府部门中直接履行监管、处罚、强制、稽查等现场执法职责的职位属于
A.综合管理类职位
B.行政执法类职位
C.其他类别职位
D.专业技术类职位
[答案]B
6.下列选项中,属于单纯性免职的是
A.晋升职务
B.离职学习连续一年以上
C.辞退
D.转任职位
[答案]B
1。
中国石油大学工程力学第二次作业答案各位石油大学机械制造及自动化专业的朋友们此答案为1309级工程力学第二次作业答案以下没有显示试题目,答案全是对的,可以抄写过去即可。
有意可加QQ 928802282单选题 (共40道题)收起1.(2.5分)•A、.•B、.我的答案:C 此题得分:2.5分3.(2.5分)•A、.•B、.•C、.•D、.我的答案:A 此题得分:2.5分4.(2.5分)•A、.•B、.•C、.•D、.我的答案:A 此题得分:2.5分5.(2.5分)•A、.•B、.•C、.•D、.我的答案:A 此题得分:2.5分6.(2.5分)•A、.•B、.•C、.•D、.我的答案:A 此题得分:2.5分7.(2.5分)•A、.•B、.•C、.•D、.我的答案:A 此题得分:2.5分8.(2.5分)•A、.•B、.•C、.•D、.我的答案:C 此题得分:2.5分9.(2.5分)•A、.•B、.•C、.•D、.我的答案:B 此题得分:2.5分10.(2.5分)•A、.•B、.•C、.•D、.我的答案:C 此题得分:2.5分11.(2.5分)•A、.•B、.•C、.•D、.我的答案:C 此题得分:2.5分12.(2.5分)•A、.•B、.•C、.•D、.我的答案:D 此题得分:2.5分13.(2.5分)•A、.•B、.•C、.•D、.我的答案:D 此题得分:2.5分14.(2.5分)•A、.•B、.•C、.•D、.我的答案:B 此题得分:2.5分15.(2.5分)•A、.•B、.•C、.•D、.我的答案:C 此题得分:2.5分16.(2.5分)•A、.•B、.•C、.•D、.我的答案:A 此题得分:2.5分17.(2.5分)•A、.•B、.•C、.•D、.我的答案:B 此题得分:2.5分18.(2.5分)•A、.•B、.•C、.•D、.我的答案:D 此题得分:2.5分19.(2.5分)•A、.•B、.•C、.•D、.我的答案:B 此题得分:2.5分20.(2.5分)•A、.•B、.•C、.•D、.我的答案:D 此题得分:2.5分21.(2.5分)•A、.•B、.•C、.•D、.我的答案:B 此题得分:2.5分22.(2.5分)•A、.•B、.•C、.•D、.我的答案:D 此题得分:2.5分23.(2.5分)•A、.•B、.•C、.•D、.我的答案:B 此题得分:2.5分24.(2.5分)•A、.•B、.•C、.•D、.我的答案:B 此题得分:2.5分25.(2.5分)•A、.•B、.•C、.•D、.我的答案:D 此题得分:2.5分26.(2.5分)•A、.•B、.•C、.•D、.我的答案:C 此题得分:2.5分27.(2.5分)•A、.•B、.•C、.•D、.我的答案:A 此题得分:2.5分28.(2.5分)•A、.•B、.•C、.•D、.我的答案:C 此题得分:2.5分29.(2.5分)•A、.•B、.•C、.•D、.我的答案:B 此题得分:2.5分30.(2.5分)•A、.•B、.•C、.•D、.我的答案:C 此题得分:2.5分31.(2.5分)•A、.•B、.•C、.•D、.我的答案:A 此题得分:2.5分32.(2.5分)•A、.•B、.•C、.•D、.我的答案:B 此题得分:2.5分33.(2.5分)•A、.•B、.•C、.•D、.我的答案:C 此题得分:2.5分34.(2.5分)•A、.•B、.•C、.•D、.我的答案:A 此题得分:2.5分35.(2.5分)•A、.•B、.•C、.•D、.我的答案:D 此题得分:2.5分36.(2.5分)•A、.•B、.•C、.•D、.我的答案:C 此题得分:2.5分37.(2.5分)•A、.•B、.•C、.•D、.我的答案:A 此题得分:2.5分38.(2.5分)•A、.•B、.•C、.•D、.我的答案:C 此题得分:2.5分39.(2.5分)•A、.•B、.•C、.•D、.我的答案:B 此题得分:2.5分40.(2.5分)•A、.•B、.•C、.•D、.我的答案:A 此题得分:2.5分。
《中级财务会计》(二)作业答案(仅供参考)第一次作业习题一1、借:在途物资 901860应交税费——应交增值税(进项税) 153140贷:银行存款 1055000借:原材料 901860贷:在途物资 9018602、借:应收账款 1170000贷:主营业务收入 1000000应交税费——应交增值税(销项税) 170000借:主营业务成本 750000贷:库存商品 750000借:主营业务税金及附加 100000贷:应交税费--应交消费税 1000003、借: 银行存款 15000累计摊销 75000贷:无形资产 80000应交税费-应交营业税 750营业外收入-出售无形资产利得 92504、借:原材料 69600应交税费-应交增值税(进项税额) 10400贷:库存现金 800005、借:委托加工物资 100000贷:原材料 100000借:委托加工物资 25000应交税费-应交增值税(进项税额) 4250贷:银行存款 29250借:委托加工物资 2500贷:银行存款 2500提示:直接对外销售的,不得抵扣消费税,应计入委托加工物资的成本。
6、借:固定资产 180000应交税费--应交增值税(进项税额)30600贷:银行存款 2106007、借:在建工程 58500贷:原材料 50000应交税费--应交增值税(进项税额转出)85008、借:待处理财产损益-待处理流动资产损益4000贷:原材料 4000习题二甲:借:应付账款 3500000存货跌价准备 150000资本公积--其他资本公积 100000贷:主营业务收入 1800000应交税费-应交增值税(销项税额) 306000可供出售金融资产—A公司股票(成本) 150000可供出售金融资产(公允价值变动) 100000投资收益 50000营业外收入-债务重组收益 1344000借:主营业务成本 2000000贷:库存商品 2000000乙: 借: 交易性金融资产 300000坏账准备 1050000存货 1800000应交税费-应交增值税(进项税额) 306000营业外支出--债务重组损失 44000贷:应收账款 3500000习题三:1、辞退福利的含义及其与职工养老金的区别P180答:企业可能出现提前终止劳务合同、辞退员工的情况。
第2次作业一、多项选择题(本大题共60分,共20小题,每小题3分)1.枢纽变电所的特点有()。
A.电压等级高;B.传输容量大;C.负荷小;D.停电影响范围大;2.下列选项中属于单母线接线优点的是()。
A.便于扩建;B.可靠性高;C.接线简单;D.投资少;3.发热对电气设备会产生哪些影响?()A.使运行电流增大;B.使金属材料的机械强度下降;C.使导体接触部分的接触电阻增加;D.使绝缘材料的绝缘性能降低;4.关于母线的作用,下面正确的是()。
A.将母线分段的目的是提高供电可靠性;B.加旁路母线的目的是在检修时不中断回路供电;C.母线的作用是汇集与分配电能;D.母线中电流一般比较小;5.对于圆管形导体,吸收太阳辐射能量的多少和下列哪个选项有关()。
A. 太阳辐射功率密度;B.导体的吸收率;C.导体的比热容;D.导体直径;6.下面属于一次设备的是()。
A.发电机;B.电流互感器;C.通讯光纤;D.断路器;7.关于厂用电备用电源的说法,正确的是()。
A.厂用电备用电源的备用方式分明备用和暗备用;B.当单机容量大于200MW时,需设置厂用启动电源;C.厂用备用电源是厂用电的一种;D.厂用备用电源对可靠性要求不高;8.厂用电各级电压母线按锅炉分段的接线方式有何优点()。
A.若某一段母线发生故障,只影响其对应的一台锅炉的运行,使事故影响范围局限在一机一炉;B.厂用电系统发生短路时,短路电流较小,有利于电气设备的选择;C.能保证电压波动在可接受的范围内;D.将同一机炉的厂用电负荷接在同一段母线上,便于运行管理和安排检修;9.根据电气设备和母线布置特点,室外配电装置通常分为()。
A.中型配电装置;B.低型配电装置;C.高型配电装置;D.半高型配电装置;10.为提高导体的载流量,应采取措施是()。
A.采用电阻率较小的材料,如铝、铝合金等;B.改变导体的形状,增加导体散热表面积;C.导体布置采用散热效果最佳的方式;D.采用电磁屏蔽,进而降低导体发热;11.以下哪些情况下可不校验热稳定或动稳定()。
第2次作业一、阅读理解(本大题共100分,共5小题,每小题20分) 1.Prehistoric men and women enjoyed a more varied diet than people do now, since they ate species of plant and several hundreds thousands types of living things. But only a tiny percentage of these were ever domesticated. Modern shops have hastened a trend towards specialization which began in the earliest days of agriculture. The food of the rich countries has become cheaper relative to wages. It is speedily distributed in supermarkets. But the choice annually becomes less and less great. Even individual foods themselves become more standardized. We live in theworld of carrot specially blunted in order to avoid making a hole in the bag, and the tomato grown to meet a demand for a standard weight of weighting tomatoes to a kilo. Siri von Reis asks: "Only the three major cereals (谷物类食物)and perhaps ten other widely cultivated species stand between famine and survival for the world" s human population and a handful of drug plants has served Western civilization for several thousand years. A rather obvious question arises: Are we missing something?” After all, there are 800 000 species of plant on earth.(1). Tn prehistoric times people.A.ate much more than we do todayB.lived mainly on plant foodC.had a wide-ranging dietD.were more fussy about what they ate(2).Most of us have come to expectA.no variation in our dietB. a reduction in food suppliesC. a specialist dietD.food conforming to a set standard(3). The specialization of food was started byA .B . the emergence of supermarkets the rise of agriculture the rich countries the modern shops (4).According to the passage, people in the West today survive on.A.carrots and tomatoesB.several thousand types of plants and cerealsc.a very small number of cultivated foodsD. special species planted one thousand years ago(5). The conclusion seems to be that we.A.could make use of more natural speciesB.don't cultivate the right kind of foodc.produce more food than we needD.cultivate too many different species2.human body is distributed (分布)in two different ways. Some fat people have a large chest and no waistline(腰身),looking rather like apples. Others are fatter below the waist, looking more like pears.Doctors in Cambridge, England have been examining the relationship between health and fat (脂肪)distribution. They find that the pear- shaped fat people have fewer problems than the apple-shaped fat people. What seems to be most important is not how much fat you have but where you have it. The doctors measured the apple-shaped women and peai,--shaped women with X-ray scanners (X 光扫描器).Human beingshave two types of fat:one is outside fat, that is the fat below the skin, and the other is inside fat that lies inside the body. Using the X-ray scanners, the doctors found that the “apples” have a large amoun t of inside fat.Tf this inside fat is much more than outside fat, it wi11 probably cause heal th problems such as obesi ty (月巴月半症). The best treatment for obesity is to reduce the inside fat. But unfortunately diet treatment (饮食疗法)simply makes an apple-shaped person into a smaller apple and a pear-shaped person into a smaller pear. At the moment there is no effective way of reducing the inside fat.(1).According to the relation between heal th and fatnessA.apple-shaped fat people have fewer problems than pear-shaped peopleB.it' s better to be apple-shaped than to be pear-shapedc.it' s better to be pear-shaped than to be apple-shapedD. fatness is the most dangerous enemy to health(2). The most important thing about fat people seems to beA.the amount of fat they haveB.the knowledge of which typo of the fat people they belong toC.the amount of the outside fat they haveD.the place where they have the fat(3).The basic reason why some people suffer from obesity is that •A.they take very little exercise every dayB.they have much more inside fat than is neededc.they are examined by X-ray scanners quite oftenD.they eat too much(4).According to what is mentioned in the passage, the best treatment for obesity at present is .A.to reduce the amount of food and drinksB.to make the body shape smallerC.already known to those people in troubleD.still to be found.3.University of Arizona researcher Dr. William Rathji says that after a study based on looking into garbage cans, the average family wastes at least $150 per year in food."Homemakers go out of their way to save pennies at the store and thendon't real ize that waste of edible (可食用的)foods adds up much moreat homo," said Dr. Rathji. He was one of about 100 food experts who metin Boise for a conference on food waste and ways to prevent it.American families throw out between 8% and 20% of edible food at a costof $4. 5 billion per year. That" s almost as much as the federal government spends every year for food stamps and child nutrition programs.He found that food items which are costly and in short supply tend to be wasted more. During the 1973 meat shortage, meat waste increased to 9%, compared with 3% in 1974 and 1975. Sugar and sugar products waste jumped to 19% in 1975, when sugar prices doubled from the previous year.Dr. Rathji theorizes that high prices force consumers to experiment, sometimes buy in large quantities. In the case of meat, sometimes low-priced cuts for unappetizing varieties are purchased, consumers then tend to waste more.Ilis theory is that the more variety in food bought, the more wasted. Regular bread is wasted at about a 10% rate, but specialty breads and rolls are wasted at a 20% rate.If people are eating the same thing every day, they learn how to manage it. But if you" re trying to pull something out of the cookbook every night, that's bound to be some waste.Another finding is that lower income families waste less food than middle and upper income families. And the study found that dog food, which accounts for 8% of a shopping cart, is rarely wasted. Fresh produce and frozen items arc more likely to be wasted.The study also showed people with the most knowledge of safe, edible food waste the least. Much food is tossed out because a homemaker suspects it is spoiled when it is not.(1).Large quantities of food are thrown out because a homemaker.A.thinks they are not deliciousB.says they taste bitter and hotC.thinks they smell badD.suspects they are spoiled when they are not(2).American families throw out between of edible food every year.A.5%〜8%B.8%-10%B.20%〜28%D.8%—20%(3).When sugar prices doubled, waste of sugar.A.went downB.went upc.stayed the sameD. was cut in half(4).Which of the following statements is true?A.American housewives are not good homemakers.B.Upper-income families are more wasteful than lower-income ones.c.American families throw away almost as much food as they consume.D.Americans waste a great deal of dog food.(5).When do American families waste more food?A.When prices arc high.B.When food is scarce.c.When they think it is spoiled.D. Al 1 of the above.4.Harvard University named historian Drew Gilpin Faust as its first female president on Sunday, ending a lengthy and secretive search to find a successor (接任者)to Lawrence Summers .The seven-member Harvard Corporation elected Faust, a noted scholar on History of the American South and dean of Harvards Radcliffe Institutefor Advanced Study, as the university' s 28th president.“This is a great day, and a historic day for Harvard. ” James R. Houghton, chairman of the presidential search committee, said in a statement. "Drew Faust is an inspiring and accomplished leader, a superb scholar, a dedicated (献身的)teacher, and a wonderful human being."Her selection is noteworthy given the heated debates over Summers' comments that genetic differences between the sexes might help explain the lack of women in top science jobs.Faust has been dean of Radcliffe since 2001, two years after the former women" s college was combined into the university as a research center with a mission to study gender issues(性另ij问题).Some professors have quietly groused that the 371-year-old university is appointing a fifth president who is not a scientist. No scientist has had the top job since James Bryant Conant retired in 1953; its last four have come from the fields of classics, 1aw, literature and economics.Faust is the first Harvard president who did not receive a degree from the university since Charles Chauncy, a graduate of Cambridge University, who died in office in 1762. She attended the University of Pennsylvania.“Teaching staff turned to her constantly. ” said Sheldon Hackney, a former president of the University of Pennsylvania and historian who worked closely with Faust. "She' s very clear. She has a sense of humor, but she' s very strong-minded. You come to trust in her because she' s so solid."(1).Which is NOT true about Drew Gilpin Faust?A.She is the 28th president of Harvard University.B.She is a famous scholar from the American South.c.She isn' t a graduate from Harvard University.D.She was head of Radcliffe Institute for Advanced Study.(2).Lawrence Summers held the view that .A.women cannot achieve as much as men in management B.women cannot hold important positions in society c.women can match men in science jobsD.few women make top scientists owing to genes (3).Which might be the best title for the passage? A.Harvard named its 1st female president.B.History of Harvard University changed.c.Debates on female equality ended.D.Drew GiIpin Faust, a famous woman historian.(4).This passage probably appears in a .A.biographyB.personal letterc.research paperD.newspaper report5.Jessica Alba rebelled(叛离)from her "strict" parents when she was just five. The 29-year-old actress admits her Catholic (天主教)education made her want to "break away" from her mother Catherine and father Mark.She explained: 〃It‘s always been weird(古怪的)because I grew up in a very traditional, Catholic household. Nly parents were very strict but 1 broke away from that at an early age. 1 was a feminist (女权主义者)when 1 was five. These days, 1 am much more independent but 1 still respect their beliefs.,zAs Jessica has grown older she has learnt to accept her parents' views, but still considers herself an independent woman.Tn her latest film 'Machete' Jessica gets to stab(刺)a love rival in the eye with her stiletto heels (鞋后世艮),something she thoroughlyenjoyed.She said: "Walking in 3in heels wasn't as much fun as putting one in someone's eye. It was 104 degrees where we were shooting in Texas and they were not comfortable.Jessica - who has a two-year-old daughter Honor with husband Cash Warren - is regularly referred to as one of the world,s most beautiful women, but she docsn't think of herself as 〃sexy〃.She added in an interview with the Metro newspaper: 〃1 don't really pay attention to that sexy image. It just goes with the character in the movie. At the end of the day, it's all a part of selling a product. 〃(1).Jessica Alba called herself feminist because .A.she didn' t like living with her parentsB.she was brought up in a very poor familyc.she was often against her parentsD.she refused the training and education during her childhood by her parents(2).From this passage we know that .A.Jessica is a very cruel woman who enjoys hurting others B.Jessica acted strangely in her chi 1drenc.Jessica" s parents believe in CatholicD.Jessica rebelled her family because she hated Catholic (3).This passage is mainly about .A.a rebellious movie star JessicaB.a weird womanc.an interview with a newspaperD.a rebellious heart(4).Which of the following statements is not true according to the passage?A.Although she is a rebellious woman, she still respects her parents beliefsB.She likes her characters in the moviec.She cares more about her sexy image because she is very proud of her beautyD.She got married and has a daughter.答案:一、阅读理解(100分,共5题,每小题20分)(1). C (2). D (3). B (4).2.(1). A (2). D (3). D (4).3.(1). D (2). D (3). B (4).4.(1). B (2). D (3). A (4).5. C (5). A CB (5). D D。
班级:学号:姓名:微观经济学第二次作业(第三章效用论、第四章生产论)一、选择题1.序数效用论认为,商品效用的大小(D )。
A.取决于它的使用价值B.取决于它的价格C.不可比较D.可以比较2.无差异曲线的形状取决于(A )。
A.消费者偏好B.消费者收入C.所购商品的价格D.商品效用水平的大小3.无差异曲线为斜率不变的直线时,表示相结合的两种商品是(B )。
A.可以替代的B.完全替代的C.互补的D.互补相关的4.同一条无差异曲线上的不同点表示(B )。
A.效用水平不同,但所消费的两种商品组合比例相同B.效用水平相同,但所消费的两种商品的组合比例不同C.效用水平不同,两种商品的组合比例也不相同D.效用水平相同,两种商品的组合比例也相同5.预算线的位置和斜率取决于(B )。
A.消费者的收入B.消费者的收入和商品价格C.消费者的偏好D.消费者的偏好.收入和商品价格6.总效用达到最大时,( A )。
A.边际效用为零B.边际效用最大C.边际效用为负D.边际效用为正7.无差异曲线的斜率被称为( A )。
A.边际替代率B.边际技术替代率C.边际转换率D.边际效用8.消费者剩余是消费者的(B )。
A.实际所得B.主观感受C.变相所得D.实际损失9.某些人在收入较低时购买黑白电视机,在收入提高时,则去购买彩色电视机,黑白电视机对这些人来说是( C )。
A.生活必需品B.奢侈品C.低档商品D.吉芬商品10.某低档商品的价格下降,在其他情况不变时,(C )。
A.替代效应和收入效应相互加强导致该商品需求量增加B.替代效应和收入效应相互加强导致该商品需求量减少C.替代效应倾向于增加该商品的需求量,而收入效应倾向于减少其需求量D.替代效应倾向于减少该商品的需求量,而收入效应倾向于增加其需求量11.恩格尔曲线可以从(B )导出。
A.价格-消费线B.收入-消费线C.需求曲线D.无差异曲线12.需求曲线斜率为正的充要条件是( D )。
A.低档商品B.替代效应超过收入效应C.收入效应超过替代效应D.低档商品且收入效应超过替代效应13.若消费者的消费低于他的预算线消费,则消费者(A )。
A.没有完全用完预算支出B.用完了全部预算支出C.或许用完了全部预算支出D.处于均衡状态14.已知X商品的价格为5美元,Y商品的价格为2美元,如果消费者从这两种商品的消费中得到最大效用时,商品Y边际效用为30,那么此时X商品的边际效用为( D )A.60 B.45 C.150 D.7515. 在追求利润的过程中,厂商要回答的问题是( D )。
A.何时生产,如何生产B.如何生产,为什么生产C.生产什么,何时生产D.生产什么,如何生产16. 厂商用来生产产品的劳动、原材料和资本商品叫做( B )。
A.现付要素B.生产要素C.现付成本D.折算要素17.如果厂商A的劳动L对资本K的边际技术替代率是1/3,厂商B的是2/3,那么( D )。
A.只有厂商A的生产成本是递减的B.只有厂商B的生产成本是递减的C.厂商A的资本投入是厂商B的两倍D.如果厂商A用3单位劳动与厂商B的2单位资本相交换,厂商A的产量将增加。
18.等成本曲线平行向外移动表明( B )。
A.产量提高了B.成本增加了C.生产要素的价格按相同比例提高了D.生产要素的价格按不同比例提高了19.在边际产量发生递减时,如果要增加同样数量的产品,应该( A )。
A.增加变动生产要素的投入量B.减少变动生产要素的投入量C.停止增加变动生产要素D.同比例增加各种生产要素20.规模报酬递减是在下述( A )情况下发生的A.按比例连续增加各种生产要素B.不按比例连续增加各种生产要素C.连续的投入某种生产要素而保持其他生产要素不变D.上述都正确21.生产要素最适度组合的选择条件是( C )。
=P1/P2 MU2=P1/P2 =w/r MPK=r/w22.当生产中的两种生产要素是完全可以替代时,则下列说法正确的有( C )。
A.边际技术替代率为零B.边际技术替代率为无穷大C.边际技术替代率保持不变D.以上三种情况均有可能二、判断题1.同一杯水具有相同的效用。
×2.无差异曲线表示不同的消费者消费两种商品的不同数量组合所得到的效用是相同的。
×3.如果边际效用递减,则总效用下降。
×4.消费者剩余是消费者的主观感受。
×5.对所有人来说,钱的边际效用是不会递减的。
√6.作为消费者的合理选择,哪一种商品的边际效用最大就应当选择哪一种商品。
×7.吉芬商品是一种低档品,但低档品不一定是吉芬商品。
√8.消费者的效用最大化要求预算线与无差异曲线相交。
×9.收入-消费曲线是由于消费者收入的变化引起效用最大化变化的轨迹。
√10.预算线的平行移动说明消费者收入发生变化,价格没有发生变化。
×11.生产函数指的是要素投入量和最大产出之间的一种函数关系,通常分为固定比例生产函数和可变比例生产函数两种类型。
√12.生产函数的斜率是边际产量。
√13.如果厂商在生产过程中减少了其中一种生产要素的使用量,这种要素的边际产量上升,这时候,生产函数表现出成本递减。
√14.当总成本不变时,工资率的增长将总是导致使用更多的资本。
×15.当X 产品需要两种生产要素:A 和B ,生产函数为X=4A9B 。
如果A 、B 价格相等,企业应使用同量的A 和B 。
√16.如果生产要素A 的边际实物产量(MPa )与A 的使用量之积总是等于要素B 的边际实物产量(MPb )与B 的使用量之积,那么,如果A 的价格是B 的两倍,则一个追求成本最小化企业应该使用两倍于A 的B 要素量。
√17.在生产过程中,当边际实物产量大于平均实物产量时,劳动的边际实物产量一定随着雇佣水平的提高而降低。
×18.规模收益递减是边际收益递减造成的。
×19.等成本曲线的斜率等于纵轴表示的生产要素Y 的价格与横轴表示的生产要素X 的价格之比。
×20.只要总产量减少,边际产量一定是负数。
√三、计算题1. 已知某消费者每年用于商品1和商品2的收入为540,两商品的价格分别为P 1 = 20元,P 2 = 30元,该消费者的效用函数为2123U X X =,该消费者每年购买这两种商品的数量各是多少每年从中获得的总效用是多少2. 设有一居民李四效用函数为1344(,)U x y x y =,其中x 为食品消费量,y 为其他商品的消费量,且该居民的收入为5000元,x 与y 的价格为10元,请计算:(1)该居民的最有消费组合。
(2)若政府提供该居民2000元的食品兑换券,此兑换券只能用于食品消费,则该居民的消费组合有何变化(厦门大学2003研)3. 已知生产函数22(,)20.50.5Q f L K KL L K ==--,假定厂商目前处于短期生产且10K =。
(1)写出在短期生产中该厂商关于劳动的总产量L TP 函数、劳动的平均产量L AP 函数和劳动的边际产量L MP 函数。
(2)分别计算当就劳动的总产量L TP 、劳动的平均产量L AP 和劳动的边际产量L MP 各自达到极大值时的厂商的劳动投入量。
(3)什么时候L AP = L MP 它的值又是多少4. 已知某企业的生产函数为2133Q L K =,劳动的价格为2w =,资本的价格为1r =。
求:(1)当成本3000C =时,企业实现最大产量时的L 、K 和Q 的均衡值。
(2)当产量Q = 800时,企业实现最小成本时的L 、K 和C 的均衡值。
四、论述题:1. 我国许多大城市,由于水源不足,自来水供应紧张,请根据边际效用递减规律,设计一种方案供政府来缓解或消除这个问题。
并请回答:(1)这种措施对消费者剩余有何影响(2)这种措施对生产资源的配置有哪些有利或不利的效应(3)这种措施对于城市居民的收入分配有哪些有利或不利的影响能否有什么补救的办法答:可用提高自来水的使用价格来缓解或消除这个问题。
自来水价格提高,一方面,用户会减少(节约)用水;另一方面,可扩大自来水的生产或供给。
这样,自来水供给紧张的局面也许可得到缓解或消除。
(1)采取这一措施,会使用户消费者剩余减少。
在图3-3中,横轴代表自来水的数量,纵轴代表自来水的价格。
直线d代表自来水的需求曲线。
当自来水价格从OP1提高到OP2时,用户对自来水的需求量从OQ1减少到OQ2。
于是,消费者剩余从ΔP1AC减少为ΔP2BC。
(2)对生产资源配置的有利效应是节约了用水,可使之用于人们更需要的用途上,从而使水资源得到更合理更有效的使用。
但这样做,也许会造成其他资源的浪费。
比方说,工厂里本来用水冷却物品,现在要改用电来冷却,增加了对电和有关装置的需求。
如果自来水价格过度提高,必然会带来更多其他资源的消耗。
这是不利的一面。
(3)如果城市居民收入不变,自来水的价格提高无疑是降低了居民的实际收入。
补救的办法就是各城市给居民增加货币工资或予以价格补贴。
2.试运用生产理论说明理性的厂商如何组织生产。
答:对于一种可变生产要素的情况,其最优生产投入量应在第二阶段,即在该可变要素的平均产量下降且边际产量大于零的阶段。
因为,在第一阶段,平均产量递增,若继续增加该要素的投入量,总产量和平均产量会相应增加,因而,理性的生产者将不会处于该阶段;在第三阶段,边际产量小于零,若减少该要素的投入量,总产量会相应增加,因而,理性的生产者也不会处于该阶段。
至于生产者究竟在第二阶段内的哪一点为最佳,则取决于该要素投入所能带来的收益与其花费的成本的比较。
若它带来的边际收益等于它带来的边际成本,则它的最佳投入数量就达到了。
否则,需要增加或减少投入量。
对于两种及两种以上的生产要素,其投入比例取决于边际技术替代率MRTS和各要素的价格,当MRTSLK=w/r时,要素的投入比例为最佳。
如此确定的比例有无数个,表现为等产量线和等成本线有无数个切点,这些切点构成生产的扩展线。
那么,理性的生产者应选择生产扩展线上的哪一点,取决于产品价格和要素的规模收益情况。
生产规模的确定需由收益情况来定。
如果规模收益呈递增趋势,则生产规模应继续扩大,增加使用各要素的数量;如果呈递减趋势,则生产规模应缩小,直到处于规模收益不变的阶段。