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1、初中物理计算题专题训练优秀名师资料（完整版）资料(可以直接使用，可编辑 优秀版资料，欢迎下载）初中物理计算题专题训练一、 物体振动的次数、时间和频率的计算(解题方案:理解什么叫频率。) 一只蜜蜂的翅膀5min振动了300次，频率是多少,人耳能否听到蜜蜂产生的声音, 二、电磁波的波长、频率和波速的关系(解题方案:波长、频率和波速这三个物理量中，不变的量是什么,他们的单位分别是什么,他们组成的等式是什么,) 一列电磁波的频率是50MHz，它的波长是多少,如果电磁波的频率变大，波速将 ，波长将 。 (以上两空都选填“变大”、“变小”或“不变”。) 三、关于光的反射计算(解题方案:正确理解入射角、反射
2、角、入射光线和镜面的夹角、反射光线和镜面的夹角、镜面和水平面的夹角等。可以说，找准角度是解题关键)。 (1)一束光线垂直射向平面镜，则入射角是 ，反射角是 。 (2)一束光线和水平面成30度夹角射向地面，为把光线反射到竖直的井中，平面镜和水平面的夹角是 。 四、关于平面镜成像特点的计算(解题方案:根据平面镜成像的特点，画出物体、平面镜和物体在平面镜中所成的虚像。找出所求的距离或角度。) (1)一长为0.5m的物体距离平面镜2m，则他距离平面镜中的像 ，它在平面镜中的像高 m。如果它向平面镜靠近，像将 (填“变大”、“变小”或“不变”)。 (2)一只铅笔和他在平面镜中的虚像所成的夹角是90度，则
3、铅笔和平面镜的夹角是 。 (3)如何根据钟表在平面镜中的像判断时间 解题方案:利用物体和像关于平面镜对称，从试卷的后面看钟表的像，结果就是钟表的实际时间。 五、质量、体积和密度的计算(解题方案:对固体和液体来说，质量、密度和体积，不变的是 ，对气体来说，质量、密度和体积，不变的是 。在计算过程中，注意单位的统一。第三、注意发现隐含条件。第四、空心体积的计算方法)。 3(1)、一个铁球质量是158g,体积是30cm。证明铁球是空心的并求空心部分的体积。 (2)、一只瓶子装满水，总质量是100g ，将一块质量是30g的物体投入瓶子并浸没在水中后，瓶子的总质量变为120g 。求物体的质量。 (3)、
4、一只瓶子的质量是20g，装满水后总质量为120g，装满某种液体后总质量为100g，求液体的密度。(你能求瓶子的容积吗,) 1 33(4)一只瓶子装有30cm的某种液体，总质量是54g;当液体体积为40cm时，总质量为62g 。求瓶子的质量和液体的密度。 六、路程、时间和速度的计算(解题方案:路程、速度和时间的单位要对应;其次要将所求的物理量用已知的物理表达出来，第三要理解哪个物体运动，所对应的时间、路程和速度分别是多少。这类试题在中考中比较简单。) (1)一列长100m的火车穿过一座长200m的大桥用了10s，求火车的速度。 (2)一个人站在高山前对着高山大喊一声后，4S听到回声，人离高山多远
5、。(声音速度是340m/s)。 (3)汽车在平直公路上以20m/s的速度向高山行驶，鸣笛后4S听到回声，则鸣笛处距离高山多远。(声音的速度是340m/s)。 七、重力和质量的关系(解题方案:准确将重力和质量的关系记准。) (1)20kg的物体受到的重力是多大, (2)一物体挂在弹簧测力计下静止时，弹簧测力计的读数是19.6N，物体的质量是多大, 八、固体压力和压强的计算(解题方案:静止的物体受到平衡力。分析接触面对物体的支持力和那些力平衡，利用平衡力求出支持力，根据支持力求出压力。分析受力面积是多大。然后求出物体对接触面的压强。) (1)一边长为10cm、质量是2kg的正方体在竖直向上的100
6、N的推力作用下静止在天花板上。求正方体对天花板的压强。(g=10N/kg) (2)一边长为10cm、质量是2kg的正方体在水平向右的100N的推力作用下静止在竖直墙面上。求正方体对墙面的压强。(g=10N/kg) 2 九、液体的压力和压强(解题方案:液体对接触面的压力和重力的关系不确定。所以一般先算压强，再根据压强和受力面积计算压力。如果容器是柱形容器，也可以先计算压力，在计算压强。) 22(1) 一容器质量是0。5kg,底面积是200cm,放在面积是1m的水平桌面的中间。容器内装1kg水，水深20cm。(g=10N/kg)求:水对容器底的压力和压强。画出容器的大致形状;容器对桌面的压力和压强
7、。 十、浮力的计算(解题方案:如果物体是静止或匀速直线运动，首先分析浮力和那些力形成平衡力，然后建立等式，求出浮力。然后再考虑使用阿基米德原理来进一步计算。在使用阿基米德原理计算时，我们要求的体积是排开液体的体积。但是排开液体的体积和固体浸在液体中的体积是相等的。所以我们往往通过求固体浸在液体中的体积来计算排开液体的体积。如果物体的状态不明，我们先用比密度的方法判断物体的状态。) 3(1) 一质量是1kg、体积是1.25dm的小球，投入盛满水的容器中静止后。(g=10N/kg) 求:小球受到的浮力，小球浸入水中的体积，从容器中溢出的水的质量。 (2)一物体挂在弹簧测力计下，在空气中的读数是20
8、N，浸没在水中的读数是12N。浸没在某种液体中读数是8N。求物体和液体的密度。(g=10N/kg) (注明:“没”在浮力这部分内容中读“mo”,不读“mei”。) 十一、功和功率的计算(解题方案:首先判断做功的力多大，物体在这个力的方向上移动的距离多大。就可以计算力做的功;然后判断做功的时间，计算功率。或者根据力和物体移动的速度计算功率。) 质量是10kg的物体放在水平地面上，在水平向左的20N拉力作用下，以2m/s的速度水平向左移动10m。求:重力做功多少,拉力做功多少,拉力做功的功率多少, 十二、关于杠杆平衡条件的计算(解题方法:首先确定动力和阻力，然后通过作图方式确定动力臂和阻力臂。然后
9、利用杠杆平衡条件计算。这部分计算很简单，关键是通过作图确定力臂。) 一质量忽略不计的扁担长1.2m，前端挂80N的物体，后端挂40N的物体。为了让扁担在水平位置平衡，肩膀应前端多远。 3 十二、关于滑轮(组)的距离、力的相关计算(解题方案:准确判断动滑轮上的绳子股数是关键，判断物体和谁是整体是技巧，画图分析是方法)。 如图，动滑轮总重,，物体重,，在拉力,的作用下匀速上升,，用时,，则,是多大,自由端上升多少米，自由端移动的速度是多大。 如图，,两图中，物体重力均为,，滑轮重力是,，不计摩擦，,两图中，物体重力均为,，不计滑轮的重力和轮上的摩擦，物体和地面摩擦均为,，四图中物体移动路程都是,，
10、时间都是10S，且匀速直线运动，四图中拉力,分别是 、 、 、 ，拉力移动的路程分别是 、 、 、 。拉力移动的速度分别是 、 、 、 。 ，十三、机械效率(解题方案:机械对物体做的功是有用功，拉力对整体做的功是总功。根据功的计算公式把有用功和总功表示出来，再根据物体移动的路程和拉力移动的路程的关系进行化简即可完成。毕节地区中考几乎考察滑轮(组)的机械效率)。 如图，动滑轮总重,，物体重,，(不计绳重和摩擦)求滑轮组的机械效率。 十四、物体吸热或放热的计算(解题方案:根据质量密度和体积的关系，计算物体的质量，再根据温度的变化判断初温和末温。带入公式即可计算。注意:从10?升高(了)20?和从1
11、0?升高到20?的区别。 一水箱容积为60L，现将半箱20?的水在标准大气压下烧开，吸收多少热量, 4 1、一辆使用汽油为燃料的汽车，以72km/h的速度在水平路面上匀速行驶时，发动机的实际7功率为20 kW。若小汽车行驶的距离为100km，汽油的热值q,4.610J/kg，小汽车发动机的效率为25,。求小汽车在这段路程中: (1)运动的时间;(2)发动机所做的功;(3)消耗汽油的质量。 2、如图所示是一直流电动机提升重物的装置。已知重物质量m=50kg,电源电压U=110V保持不变，电动机线圈的电阻R=4欧，不计各处摩擦，当电动机以某一速度匀速向上提升重物时，电路中的电流I=5A(g=10N
12、/kg)。求: ? 电源的输出功率是多少, ? 电动机线圈电阻R的发热功率 ? 试从能量的转换和守恒角度，求重物上升的速度大小. 3、马玲家买了一台电热水器，铭牌上部分参数如图所示。求: (,)、热水器正常工作的电流和电阻。 容积 , 额定电压 , 额定功率 ,(, (,)、若在用电高峰时，电路中的实际电压只有,，热水器把满壶水从,?加热到,?需要,(则热水器在此加热过程中的效率是多少,(不考虑电阻随温度的变化。)(,年毕节地区中考题) 十七、电路的简单计算(解题方案:确定电路中不变的量，再判断电路的连接方式，从而确定电路中电流、电压和电阻的关系，如果电路连接方式不明，先判断电路的连接方式，最
13、后依据欧姆定律求解。) ,、如图，电压表的示数是6V，电流表的示数是0.4A，虚线框内由两只 电阻组成的电路。其中,欧。通过计算确定两只电阻的连接方式; ,求,的电压和,的阻值。 ,5 ,、.如图所示，灯L标有“3V 1.5W“字样，R=3， 2当S、S、S闭合时，灯L恰正常发光;当开关S闭合，S，S断开1212时， 电流表示数为0.6A。求: (1)电源电压; (2)请用两种不同方法计算出电阻R的阻值。(设电源电压不变) 13、如图 (a)所示的电路中，电源电压不变。闭合开关后(滑片由b端向a端移动过程中，电压表示数U与电流表示数I的关系如图 (b)，求:电源电压，电阻R;滑动变阻器的最大阻
14、值。 (a) 十八、关于电能表的计算(解题方案:正确理解电能表上所标明的电流是最大电流。根据电压和最大电流可以求出家庭电路中允许使用的最大电功率。根据电能表转动的转数(或闪烁的次数)求出用电器消耗的电能，再根据电能和时间计算用电器的电功率。) 一只电能表上标有“220 5(10) 3000imp/kw.h”字样。将一台电磁炉单独连入该电路中，5min观察到指示灯闪烁了300次，求:该电路允许使用的最大电功率是多少,电磁炉的电功率是多大, 十九、单个用电器电功率的计算(解题方案:在不计温度影响时，用电器的电阻不变。在用电器正常工作的情况下，求出用电器的电流和电阻。不正常工作时，用电器的电阻不变。
15、利用实际电压和电阻完成计算)。 一只灯泡标有“pz220100”字样。实际电压是110V时，实际电功率是多大,(不计温度对电阻的影响)。 二十、在电路中分析电功率(解题方案:首先要分析是电路的总功率还是单个电阻的功率。22电路的总电压不变，所以一般选择P=U/R分析计算;如果是电阻的电功率，我们一般选择P=IR.这样选择公式，我们只需判断电阻的大小或电流的大小即可完成计算。尽量减少计算。 6 (1)、一只标有“PZ 220100”字样的电灯，将它和一只最大电阻为484欧的滑动变阻器串联后连入家庭电路中。求灯泡电功率的变化范围。(不计温度对电阻的影响) (2)、小芳家里的某品牌电烤箱铭牌及其内部
16、简化电路如图所示，R和R均为电热丝。求: 12?电烤箱在高温档工作时，开关S应 ，S应 (都填断开或闭合)。 12?若某种食物需要用该电烤箱高温档烘烤1000s，则该电烤箱消耗的电能是多少, ?电路中R的阻值是多少, 1?该电烤箱在低温挡正常工作时，电路中的电流和R的功率分别是多少, 1二十一、关于焦耳定律(电热)的计算(解题方案:首先要分析这个电路是否把电能全部转化成内能。如果是，则Q=W=Pt，我们可以通过计算电能以求放出的热量，这个方法可应用于2电热器;如果不是，则WQ=IRt。我们只能通过焦耳定律求电热了，则个方法可以用于电动机。此时不仅可以求出电动机产生的电热，还能求出电动机的机械能
17、。 (1)、一只电烙铁的电功率是50W，正常工作5min产生的热量是多少, (2)、一台电动机线圈电阻是4欧，两端电压为80V，产生电流为5A。求电动机将电能转化为机械能的效率。 二十二、如何根据电池的容量和充电电压求电能 电池的容量就是电池充电达到饱和时装入的电荷量Q。Q=It。例如电池容量为120Ah 它的意思就是Q=120A3600S。如果再知道充电电压为5V;根据电能的计算公式W=Pt=UIt=5V120A3600S=xJ. 某人 电池板上注明:充电电压4V，电池容量480Ah 。请你计算他的 电池板充足电能充入多少电能, 7 (英文版 ) Two regulations promul
18、gated for implementation is in the party in power for a long time and the rule of law conditions, the implementation of comprehensive strictly strategic plan, implementation in accordance with the rules and discipline to manage the party, strengthen inner-party supervision of major initiatives. The
19、two regulations supporting each other, the adhere to a positive advocate, focusing on morality is of Party members and Party leading cadres can see, enough to get a high standard; around the party discipline, disciplinary ruler requirements, listed as negative list, focusing on vertical gauge, draw
20、the party organizations and Party members do not touch the bottom line . Here, the main from four square face two party rules of interpretation: the first part introduces two party Revised regulations the necessity and the revision process; the second part is the interpretation of the two fundamenta
21、l principles of the revision of laws and regulations in the party; the third part introduces two party regulations modified the main changes and needs to grasp several key problems; the fourth part on how to grasp the implementation of the two regulations of the party. and revised the necessity and
22、revised history of the CPC Central Committee the amendment to the Chinese Communist Party members and leading cadres honest politics several guidelines and column 1 by 2021 to strengthen 8 party laws and regulations focus. Two party regulations revision work lasted a Years, pooling the wisdom of the
23、 whole party, ideological consensus, draw historical experience, respect for the wisdom of our predecessors, which reflects the unity of inheritance and innovation; follow the correct direction, grasp the limited goals, adhere to the partys leadership, to solve the masses of the people reflect a foc
24、us on the problem. The new revision of the and , reflects the partys 18 and the eighth session of the third, the spirit of the fourth plenary session, reflecting the experience of studying and implementing the General Secretary Xi Jinping series of important speech, reflects the partys eighteen year
25、s comprehensive strictly practice. (a) revised two regulations of the party need of in based on revised, the promulgation and implementation of January 2021, to strengthen the construction of the contingent of leading cadres play an important role. But with the party to manage the party strictly adm
26、inistering the deepening, has not been able to fully meet the actual needs. Content is too complicated, eight prohibition, 52 are not allowed to hard to remember, and also difficult to put into practice; the second is concisely positive advocated by the lack of prohibited provisions excessive, no au
27、tonomy requirements; the third is banned terms and discipline law, both with the party discipline, disciplinary regulations 9 repeat and Criminal law and other laws and regulations repeat; the fourth is to clean the theme is not prominent, not for the existing problems, and is narrow, only needle of
28、 county-level leading cadres above. is in 1997 based on revision, in December 2003 the promulgation and implementation, to strengthen the construction of the party play very important role. Along with the development of the situation, which many provisions have been unable to fully meet the comprehe
29、nsive strictly administering the practice needs. One is Ji law, more than half of the provisions and criminal law and other countries laws and regulations Repetition; two is the political discipline regulations is not prominent, not specific, for violation of the party constitution, damage the autho
30、rity of Party Constitution of misconduct lack necessary and serious responsibility to pursue; third is the main discipline for the leading cadres, does not cover all Party members. Based on the above situation, need to and the two is likely to be more relevant regulations first amendment. By revisin
31、g, really put the authority of Party discipline, the seriousness in the party tree and call up the majority of Party members and cadres of the party constitution of party compasses party consciousness. (II) two party regulations revision process the Central Committee of the Communist Party of China
32、attaches great importance to two regulations revision . Xi Jinping, general books recorded in the Fifth 10 Plenary Session of the eighth session of the Central Commission for Discipline Inspection, on the revised regulations made clear instructions. According to the central deployment, the Central C
33、ommission for Discipline Inspection from 2021 under six months begin study two regulations revision. The Standing Committee of the Central Commission for Discipline Inspection 4 review revised. Comrade Wang Qishan 14 times held a special meeting to study two regulations revision, amendment clarifies
34、 the direction, major issues of principle, path and target, respectively held a forum will listen to part of the province (area) secretary of the Party committee, Secretary of the Discipline Inspection Commission, part of the central ministries and state organs Department The first party committee i
35、s mainly responsible for people, views of experts and scholars and grassroots party organizations and Party members. Approved by the Central Committee of the Communist Party of China, on 7 September 2021, the general office of the Central Committee of the Party issued a notice to solicit the provinc
36、es (autonomous regions, municipalities) Party, the central ministries and commissions, state ministries and commissions of the Party (party), the General Political Department of the military, every 3 people organization of Party of two regulations revision opinion. Central Commission for Discipline
37、Inspection of extensive solicitation of opinions, careful study, attracting, formed a revised sent reviewers. In October 8 and October 12, Central Committee Political 11 Bureau Standing Committee and the Political Bureau of the Central Committee After consideration of the two regulations revised dra
38、ft. On October 18, the Central Committee of the Communist Party of China formally issued two regulations. Can say, two laws amendment concentrated the wisdom of the whole party, embodies the party. Second, and revision of the basic principles of two party regulations revision work and implement the
39、partys eighteen, ten eight plenary, the spirit of the Fourth Plenary Session of the Eleventh Central Committee and General Secretary Xi Jinping important instructions on the revised and , highlighting the ruling party characteristics, serious discipline, the discipline quite in front of the law, bas
40、ed on the current, a long-term, advance as a whole, with Bu Xiuding independent and . Main principle is: first, adhere to the party constitution to follow. The constitution about discipline and self-discipline required specific, awaken the party constitution of party compasses party consciousness, m
41、aintaining the authority of the constitution. General Secretary Xi Jinping pointed out that no rules, no side round. Party constitution is the fundamental law, the party must follow the general rules. In early 2021 held the eighth session of the Central Commission for Discipline Inspection Fifth Ple
42、nary Session of the 16th Central Committee, Xi Jinping again pointed out that constitution is the party must follow the general rules, but also the general rules. the revision 12 of the and is Method in adhere to the regulations established for the purpose of combining rule of virtue is to adhere to
43、 the party constitution as a fundamental to follow, the constitution authority set up, wake up the party constitution and party rules the sense of discipline, the party constitution about discipline and self-discipline specific requirements. 4 second is to adhere to in accordance with the regulation
44、s governing the party and the party. The Party of rule of virtue de, mainly refers to the partys ideals and beliefs, excellent traditional style. The revised the closely linked to the self-discipline, insisting on the positive initiative, for all members, highlight the vital few, emphasized self-dis
45、cipline, focusing on the morality, and the majority of Party members and the ideological and moral standards. The revised Ji method separately, Ji, Ji Yan to Method, as a negative list, emphasizing the heteronomy, focusing on vertical gauge. Is this one high and one low, a positive reaction, the str
46、ict party discipline and practice results transformation for the integration of the whole party to observe moral and discipline requirements, for the majority of Party members and cadres provides benchmarking and ruler. Third, insist on to. In view of the problems existing in the party at the presen
47、t stage, the main problems of Party members and cadres in the aspect of self-discipline and abide by the discipline to make clearly defined, especially the partys eighteen years strict political discipline and political rules, organization and discipline and 13 to implement the central eight provisions of the spirit against the four winds and other requirements into Disci