验证机械能守恒定律实验问题归纳

验证机械能守恒定律实验问题归纳 guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation 一. 教学内容:验证机械能守恒定律实验问题归纳 二. 学习目标: 1、掌握机械能守恒定律的实验原理、实验步骤及误差。 2、深刻理解验证机械能守恒定律实验所涉及的习题类型及相关解法。 三. 考点地位: 机械能守恒定律是高中阶段实验问题的重点内容，从近几年高考试题实验题出题的特点来看，现为一电学实验和一个非电学实验的组合，验证机械能守恒定律的实验是我们备考非电学实验的重点内容。 四. 知识体系: 1、实验目的: 验证机械能守恒定律。 2、实验原理 通过实验，分别求做自由落体运动物体的重力势能的减少量和相应过程动能的增加量。若二者相等，说明机械能守恒，从而验证机械能守恒定律: (3)从打出的几条纸带中挑选第一、二点间的距离接近2mm且点迹清晰的纸带进行测量，记下第一个点的位置O，并在纸带上从任意点开始依次选取几个点1、guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation 2、3、4„„，并量出各点到O点的距离 ，计算相应的重力势能减少量 (4)测出一系列计数点到第一个点的距离 ，根据公式 。 (5)比较 是否相等。 5、实验结论 在重力作用下，物体的重力势能和动能可以互相转化，但总的机械能守恒。 即当 ，或 一定稍小于势能的减少量例1. 在验证机械能守恒定律的实验中 (1)从下列器材中选出实验所必需的，其编号为____________。 A. 打点计时器(包括纸带); B. 重物; C. 天平; D. 毫米刻度尺; E. 秒表; F. 运动小车 (2)打点计时器的安装放置要求为___________;开始打点计时的时候，应先_________，然后____________。 (3)实验中产生系统误差的原因主要是_________，使重物获得的动能往往__________。为减小误差，悬挂在纸带下的重物应选择____________。 (4)如果以 图线是_________，该线的斜率等于____________。 the functions and priorities compared to the requirements of our gap is still very big. Main is daily in the passive meet of more, active research of less, service also has not timely, and not in place of problem; work in the meet Yu traditional of, and program of of work way, develop innovation spirit and service innovation capacity not strong; supervision information work and promoted decision implementation of contact enough close, feedback situation not active; research resources of using enough full, research results of into degree not high; some sector documents running not specification; Municipal Government Office on the County (district) and municipal government sector Office work of guide enough, No real form interaction and close collaboration, promote the implementation of the work. These problems, we must effectively be addressed in the future work. Second, serve the overall situation, carry out their duties, improve quality, and strive to create a new situation of system of government offices in the city since last season, meeting the Secretary-General of the State Council and the provincial government has held a government system, from a global and strategic height, scientifically analyzed the new situation and the newTasks on the system of government offices bring new situations and new problems and new challenges, profoundly expounded the work of government departments at all levels in the new era should be put in the situation to understand, to grasp, to deploy at any time and under any circumstances, should always focus on the big picture, firmly grasp the overall situation, increasing in the overall implementing in earnest the work of spontaneity, initiative and steadfastness. And explicitly put forward the "surrounding situation, pay attention to implementation" is the core of government offices, requiring government departments at all levels cannot be "Gramophone", "mail room" and "the Messenger" is not confined to paper communications, yinglaisongwang and upload issue. Must to has strongly of implementation guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation 解析:(1)选出的器材有:打点计时器(包括纸带)，重物，毫米刻度尺，编号分别为:A、B、D。注意因 ，故m可约去，不需要用天平。 (2)打点计时器安装时，底板要竖直，这样才能使重物在自由落下时，受到的阻力较小。开始记录时，应先给打点计时器通电打点，然后再放下重物，让它带着纸带一同落下。 (3)产生系统误差的主要原因是纸带通过打点计时器时的摩擦阻力，使得重物获得的动能小于它所减少的重力势能。为减小误差，重物的质量应选大一些的。 (4)描绘出来的变式1. (2007?长春质检)用如图所示的实验装置来验证机械能守恒定律。实验所用的电源为学生电源，输出电压为6V的交变电流和直流电两种。重锤从高处由静止开始落下，重锤上拖着的纸带通过打点计时器打出一系列的点，对纸带上的点的痕迹进行测量，即可验证机械能守恒。 下面列举了该实验的几个操作步骤: A. 按照上图所示的装置安装器材; B. 将打点计时器接到电源的直流输出端上; C. 用天平测量出重锤的质量; D. 释放悬挂纸带的夹子，同时接通电源开关打出一条纸带; E. 测量打出的纸带上某些点之间的距离; F. 根据测量的结果计算重锤下落过程中减少的重力势能是否等于增加的动能。 guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation 指出其中没有必要进行的或者操作不恰当的步骤，将其选项对应的字母填在下面 的空行内，并说明其原因。 答: _____________________________________________________________________ __ _____________________________________________________________________ ____。 答案:步骤B是错误的，应该接到电源的交流输出端。步骤D是错误的，应先 接通电源，待打点稳定后再释放纸带，步骤C是不必要的，因为根据测量原理， 重锤的动能和势能都包含了质量m，可以约去。 问题2、数据的记录与处理问题: 例2. 在做验证机械能守恒定律的实验时，若打出的纸带前段不清楚，但从A ,E却是清楚的，数据如图所示，单位是cm，你能据此验证重物下落过程中机械 能是否守恒吗,要求: (1)简述判断方法; (2)写出运算过程; (3)得出结论; (4)算出A点是第几个点。 解析:(1)选定物体下落的某段距离?h，算出其重力势能减小量 ;再算出下落?h过程中动能的增加量 ， 则验证了重物下落过程中机械能守恒。 (2)根据 可得 the functions and priorities compared to the requirements of our gap is still very big. Main is daily in the passive meet of more, active research of less, service also has not timely, and not in place of problem; work in the meet Yu traditional of, and program of of work way, develop innovation spirit and service innovation capacity not strong; supervision information work and promoted decision implementation of contact enough close, feedback situation not active; research resources of using enough full, research results of into degree not high; some sector documents running not specification; Municipal Government Office on the County (district) and municipal government sector Office work of guide enough, No real form interaction and close collaboration, promote the implementation of the work. These problems, we must effectively be addressed in the future work. Second, serve the overall situation, carry out their duties, improve quality, and strive to create a new situation of system of government offices in the city since last season, meeting the Secretary-General of the State Council and the provincial government has held a government system, from a global and strategic height, scientifically analyzed the new situation and the newTasks on the system of government offices bring new situations and new problems and new challenges, profoundly expounded the work of government departments at all levels in the new era should be put in the situation to understand, to grasp, to deploy at any time and under any circumstances, should always focus on the big picture, firmly grasp the overall situation, increasing in the overall implementing in earnest the work of spontaneity, initiative and steadfastness. And explicitly put forward the "surrounding situation, pay attention to implementation" is the core of government offices, requiring government departments at all levels cannot be "Gramophone", "mail room" and "the Messenger" is not confined to paper communications, yinglaisongwang and upload issue. Must to has strongly of implementation guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation (3)若选BC段，则有 可见在误差允许的范围内 ，机械能守恒定律获证。 如选BD段，则有 在误差允许的范围内认为 ，机械能守恒定律获证。 (4)设从打第一个点到打B点所用的时间为t，则由 所以 (个)。 这表明A为第6个点。 变式2. 在做“验证机械能守恒定律”的实验时，用打点计时器打出纸带如图所示，其中A点为打下的第一个点，0，1，2，„„为连续的计数点。现测得两相邻计数点之间的距离分别为已知相邻计数点间的打点时间间隔均为T。根据纸带测量出的距离及打点的时间间隔，可以求出此实验过程中重锤下落运动的加速度大小的表达式为 ___________，在打第5号计数点时，纸带运动的瞬时速度大guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation 小的表达式为___________，要验证机械能守恒定律，为减小实验误差，应选择打下第___________号和第 ___________号计数点之间的过程来研究。 解析:用逐差法求加速度 为减小实验误差，应选择打下第1号点和第5号点之间的过程来研究。 变式3. I. 在验证机械能守恒定律的实验中， (1)某同学通过实验获得的纸带如图所示，测得所选计数点A、B之间的间隔 ，B、C两点之间的间隔 ，打点计时器所用电源的频率为 (2)该同学上交的实验显示重锤增加的动能略大于重锤减少的重力势能，则出现这一问题的原因可能是__________。 A. 实验所选重锤质量过大 B. 实验所选重锤质量过小 C. 实验时先接通电源后放纸带 D. 实验时先放纸带后接通电源 答案:(1) (2)D 问题3、实验原理或方法的迁移创新类问题: 例3. (2007?深圳期末)如图(a)所示，用包有白纸的、总质量为m的圆柱棒替代纸带和重锤，蘸有颜料的毛笔固定在马达上并随之转动，使之替代打点计the functions and priorities compared to the requirements of our gap is still very big. Main is daily in the passive meet of more, active research of less, service also has not timely, and not in place of problem; work in the meet Yu traditional of, and program of of work way, develop innovation spirit and service innovation capacity not strong; supervision information work and promoted decision implementation of contact enough close, feedback situation not active; research resources of using enough full, research results of into degree not high; some sector documents running not specification; Municipal Government Office on the County (district) and municipal government sector Office work of guide enough, No real form interaction and close collaboration, promote the implementation of the work. These problems, we must effectively be addressed in the future work. Second, serve the overall situation, carry out their duties, improve quality, and strive to create a new situation of system of government offices in the city since last season, meeting the Secretary-General of the State Council and the provincial government has held a government system, from a global and strategic height, scientifically analyzed the new situation and the newTasks on the system of government offices bring new situations and new problems and new challenges, profoundly expounded the work of government departments at all levels in the new era should be put in the situation to understand, to grasp, to deploy at any time and under any circumstances, should always focus on the big picture, firmly grasp the overall situation, increasing in the overall implementing in earnest the work of spontaneity, initiative and steadfastness. And explicitly put forward the "surrounding situation, pay attention to implementation" is the core of government offices, requiring government departments at all levels cannot be "Gramophone", "mail room" and "the Messenger" is not confined to paper communications, yinglaisongwang and upload issue. Must to has strongly of implementation guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation 时器。当烧断挂圆柱棒的线后，圆柱棒竖直自由落下，毛笔就在圆柱棒面上的纸上画出记号，如图(b)所示。测得记号之间的距离依次为26mm、42mm、 58mm、74mm、90mm、106mm，已知马达铭牌上标有“1500r/min”的字样，由此验证机械能守恒。 解析:本实验是对课本实验原理的拓展，主要考查在新情境中，对已学知识的迁移应用，考查分析、处理实际问题的综合能力，本题的关键是要明确毛笔在圆柱棒上的划痕周期与马达的转动周期相同的原理从而推出本实验的计时方式。 (1)马达的转速为1500r/min，可知其频率为 。由于棒做自由落体运动，故画线间距越靠近悬挂端越大，因此左端为悬挂端。 (2)由匀变速直线运动规律，可得圆柱棒下落速度为: 所以C、D间圆柱棒动能的变化量为: 由此可得出结论为:物体在自由下落过程中机械能守恒。 变式4. (2004?北京理综卷)在“验证机械能守恒定律”的实验中，质量为m的重锤拖着纸带下落，在此过程中，打点计时器在纸带上打出一系列的点，在纸带上选取 5个相邻计数点A、B、C、D和E，相邻计数点时间间隔为 T，其中O为重锤开始下落时记录的点，各计数点之间的距离如图所示。(当地重力加速度为g) guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation (1)打点计时器打下计数点B时，重锤下落的速度 __________，打点计时器打下计数点D时，重锤下落的速度 __________。 (2)从打下计数点B到打下计数点D的过程中，重锤的重力势能减小量 __________。 (3)在误差允许范围内，通过比较__________就可以验证重锤下落过程中机械能守恒了。 答案: 变式5. 在验证“机械能守恒定律”的实验中，已知打点计时器所用电源的频率为50Hz，查得当地的重力加速度 ，测得所用的重物的质量为1.00kg，实验中得到一条点迹清晰的纸带，如图所示。把第一个点记做O，另选连续的4个点A，B，C，D作为测量的点。经测量知道A，B，C，D各点到O点的距离分别为62.99cm、70.18cm、77.76cm、85.73cm。根据以上数据可知，重物由O点运动到C 点，重力势能的减少量等于_________J，动能的增加量等于_________J。(取三位有效数字) 根据测量数据，重物从O点运动到C点下落的高度为 根据匀变速直线运动知识，重物运动至C点时的速度 等于重物从B运动至D这一段时间内的平均速度，即 答案:7.62 7.56 【模拟试题 the functions and priorities compared to the requirements of our gap is still very big. Main is daily in the passive meet of more, active research of less, service also has not timely, and not in place of problem; work in the meet Yu traditional of, and program of of work way, develop innovation spirit and service innovation capacity not strong; supervision information work and promoted decision implementation of contact enough close, feedback situation not active; research resources of using enough full, research results of into degree not high; some sector documents running not specification; Municipal Government Office on the County (district) and municipal government sector Office work of guide enough, No real form interaction and close collaboration, promote the implementation of the work. These problems, we must effectively be addressed in the future work. Second, serve the overall situation, carry out their duties, improve quality, and strive to create a new situation of system of government offices in the city since last season, meeting the Secretary-General of the State Council and the provincial government has held a government system, from a global and strategic height, scientifically analyzed the new situation and the newTasks on the system of government offices bring new situations and new problems and new challenges, profoundly expounded the work of government departments at all levels in the new era should be put in the situation to understand, to grasp, to deploy at any time and under any circumstances, should always focus on the big picture, firmly grasp the overall situation, increasing in the overall implementing in earnest the work of spontaneity, initiative and steadfastness. And explicitly put forward the "surrounding situation, pay attention to implementation" is the core of government offices, requiring government departments at all levels cannot be "Gramophone", "mail room" and "the Messenger" is not confined to paper communications, yinglaisongwang and upload issue. Must to has strongly of implementation guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation 1、关于“验证机械能守恒定律”的实验，下列叙述正确的是( ) A. 必须用天平测出重物的质量 B. 必须采用直流低压电源 C. 必须先接通电源，后释放纸带 D. 必须用秒表测出重物下落的时间 2、下列关于“验证机械能守恒定律”实验的实验误差的说法，正确的是( ) A. 重锤质量的称量不准会造成较大误差 B. 重锤质量选用得大些，有利于减小误差 C. 重锤质量选用得小些，有利于减小误差 D. 纸带下落和打点不能同步会造成较大误差 、本实验中，除铁架台、夹子、低压交流电源、纸带和重物外，还需选用的仪3 器是( ) A. 秒表 B. 刻度尺 C. 天平 D. 打点计时器 4、在“验证机械能守恒定律”的实验中: (1)实验的研究对象是____________。 (2)供选择的重物有以下四个，应选择( )。 A. 质量为100g的钩码 B. 质量为10g的砝码 C. 质量为200g的木球 D. 质量为10g的塑料球 (3)给打点计时器提供的电源如下，应选择( )。 A. 4节干电池 B. 3节蓄电池 guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation C. 学生电源4V~6V，交流输出 D. 学生电源4V~6V，直流输出 5、用自由落体验证机械能守恒定律，就是看 (n为计时点的编号0、1、2、„„n)。下列说法正确的是( )。 A. 打点计时器打第一个点0时，物体的速度为零 B. 是计时点n到计时点0的距离 C. m为重物的质量，需用天平称量 D. 用 计算 时， ___________，重物的动能增加量 8、有位同学用落体法做验证机械能守恒定律的实验，他挑选一条第1、2两点之间的距离最接近2mm的纸带进行处理。设第一个点为A，第n个点为B，测量出AB之间的距离h，因为从开始下落到B点经过打点计时器的时间是 ，如果有 对实验条件的要求是____________，为此目的，所选择的纸带第1、2两点间的距离应接近____________。 (2)若实验中所用重锤的质量 ，打点纸带如图所示，打点时间间隔为0.02s，则记录B点时，重锤速度 ___________，重锤动能 ___________，从开始下落起至B点重锤的重力势能减少量是___________，由此可得出的结论是____________________。 the functions and priorities compared to the requirements of our gap is still very big. Main is daily in the passive meet of more, active research of less, service also has not timely, and not in place of problem; work in the meet Yu traditional of, and program of of work way, develop innovation spirit and service innovation capacity not strong; supervision information work and promoted decision implementation of contact enough close, feedback situation not active; research resources of using enough full, research results of into degree not high; some sector documents running not specification; Municipal Government Office on the County (district) and municipal government sector Office work of guide enough, No real form interaction and close collaboration, promote the implementation of the work. These problems, we must effectively be addressed in the future work. Second, serve the overall situation, carry out their duties, improve quality, and strive to create a new situation of system of government offices in the city since last season, meeting the Secretary-General of the State Council and the provincial government has held a government system, from a global and strategic height, scientifically analyzed the new situation and the newTasks on the system of government offices bring new situations and new problems and new challenges, profoundly expounded the work of government departments at all levels in the new era should be put in the situation to understand, to grasp, to deploy at any time and under any circumstances, should always focus on the big picture, firmly grasp the overall situation, increasing in the overall implementing in earnest the work of spontaneity, initiative and steadfastness. And explicitly put forward the "surrounding situation, pay attention to implementation" is the core of government offices, requiring government departments at all levels cannot be "Gramophone", "mail room" and "the Messenger" is not confined to paper communications, yinglaisongwang and upload issue. Must to has strongly of implementation guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation (3)根据纸带算出相关各点的速度v，量出下落距离h，则以 【试题答案 1、C (本题考查的是验证机械能守恒定律的实验，因为实验中根据公式 。不需要测量重物的质量。为了减小实验误差要求重物适当重些，因为实验中运用打点计时器，所以不需要秒表测时间，同时必须采用低压交流电源，应用打点计时器时应先接通电源，后释放纸带，要求被选用的纸带打出的第1、2两点间距离接近2mm，故C选项正确。) 2、B、D (本实验与重锤质量无关，但重锤质量选得大些，则空气阻力相对减小，可以忽略不计。有利于减小误差;纸带下落和打点不能同步有两种情况:?纸带先下落后打点;?重锤后下落，前者会使最初两点间距离较正常间距偏大，且第一个点便有初动能，?会造成最初几个点的点迹不清，不便于选择纸带进行测量。??均会带来较大误差。) 3、B、D (由实验仪器可知。) 4、(1)带纸带夹的重锤 (2)A guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation (3)C ,实验的研究对象是能够连接纸带的重物;为减小阻力的影响，重物应选择体积小、质量大的物体，故问题(2)中应选A;打点计时器是使用交流电工作的仪器，工作电压为4V~6V，所以问题(3)中应选C;而A、B、D皆为直流电源，不能选。, 5、A、B (本实验的原理就是利用重物的自由落体运动来验证机械能守恒定律。因此打点计时器所打的第一个点，重物运动的速度应为零， 与 分别表示打第n点时重物下落的高度和对应的瞬时速率。 本实验中，不需要测量重物的质量，因为公式 中的方程两边都有m，故只要 ，在打B点时重物的瞬时速度为 造成实验误差的主要原因在于有空气阻力及打点计时器对纸带的摩擦阻力，所以造成 。, 8、这位同学用 ，此时重锤的动能为<1" style='width:167.25pt; > ，物体的重力势能减小量为<2" height:20.25pt' > 。 ，横坐标为h，则图象应为过原点且斜率为g的直线。, the functions and priorities compared to the requirements of our gap is still very big. Main is daily in the passive meet of more, active research of less, service also has not timely, and not in place of problem; work in the meet Yu traditional of, and program of of work way, develop innovation spirit and service innovation capacity not strong; supervision information work and promoted decision implementation of contact enough close, feedback situation not active; research resources of using enough full, research results of into degree not high; some sector documents running not specification; Municipal Government Office on the County (district) and municipal government sector Office work of guide enough, No real form interaction and close collaboration, promote the implementation of the work. These problems, we must effectively be addressed in the future work. Second, serve the overall situation, carry out their duties, improve quality, and strive to create a new situation of system of government offices in the city since last season, meeting the Secretary-General of the State Council and the provincial government has held a government system, from a global and strategic height, scientifically analyzed the new situation and the newTasks on the system of government offices bring new situations and new problems and new challenges, profoundly expounded the work of government departments at all levels in the new era should be put in the situation to understand, to grasp, to deploy at any time and under any circumstances, should always focus on the big picture, firmly grasp the overall situation, increasing in the overall implementing in earnest the work of spontaneity, initiative and steadfastness. And explicitly put forward the "surrounding situation, pay attention to implementation" is the core of government offices, requiring government departments at all levels cannot be "Gramophone", "mail room" and "the Messenger" is not confined to paper communications, yinglaisongwang and upload issue. Must to has strongly of implementation guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation guide sex further enhanced, documents handle and running of speed obviously speed up, program gradually specification, conference service and Chief reception of quality and level has has new of improve, Logistics support capability further strengthened. Document management, confidential, confidentiality, duty, letters and other items have been significantly improved. 4, Office construction increased at all levels. City Government offices adhere to strengthen and improve the construction of the system as a breakthrough, has developed a series of code of conduct, continuous improvement of operational mechanism, sound and the implementation of the rules and regulations, and adhere to the system of managing people, according to the rules, the work gradually into the orbit of institutionalization and standardization. Focus on strengthening ideological and political construction of the contingent of cadres, and actively carried out various business training, knowledge of the Office team structure has been optimized, to broaden the range of knowledge and operational capacity grows, nurtured a political firm, sharp, professional and innovative staff, created solidarity, striving for the top, pragmatic, dedication, good image. However, with the State Council and the provincial Government of the national, the province's Secretary-General meeting of government offices under the new situation