promotion of employment, form a reasonable and orderly pattern of income distribution, build a more fair and sustainable social security systems, medical and health system reform. The plenary, innovation of social governance, must focus on the maintenance of fundamental interests of the overwhelming majority of the people, maximize factors, enhance social development, improving social governance, the interests of national security, ensure that the people live and work, social stability and order. o improve social governance, stimulating social organization, innovative and effective system of preventing and resolving social conflicts, improving the public security system, set up the National Security Council, national security systems and national security strategy to ensure national security. Plenary session, the construction of ecological civilization, you must establish systems of ecological system, using the system to protect the ecological environment. o improve naturalresources asset property right system and use control, red line of delimitation of ecological protection, resources paid use system and ecological compensation system in ecological environment protection management system reform. Plenary session, centering on building a listening party command, can win and having a fine style of the people's army, a strong army under the new situation of the party Goals, restricting the development of national defense and army building is solved outstanding contradictions and problems, innovation and development of military theory, enhance military strategic guidance, improve the military strategy in the new period, building a modern military force system with Chinese characteristics. o deepen the adjustment of personnel system reform in the army, military policy and system reform, promote the development of military and civilian integration depth. Plenary session stressed that comprehensive reform must be to strengthen and improve theparty's leadership, give full play to the core role of the party commands the overall situation and coordinating all parties, improving the party's leading water ... Margin. Challenged the leadership of the Communist Party of China, Marxism-Leninism and Mao Zedong thought by Deng Xiao-ping's flag, replaced by three representatives and the harmonic society. The former Communist Party spirit and social cohesion point of almost all political makeover. Characteristics of socialism public ownership is shifting to private ownership, planned regulation and market regulation, the proletarian regime controlled by the elite. Of universal equality, fairness and basic principles of distribution system is socialist society, however after economic monopolized by powerful, vested interests growemployers do not have the same status, hardly seems fair social distribution. State key protection of capital interests rather than the interests of citizens, had been hits the bottom of the proletariat 第一章 静电场
4 电势能和电势
教学目标
1、理解静电力做功的特点、电势能的概念、电势能与电场力做功的关系。 2、理解电势的概念,知道电势是描述电场的能的性质的物理量。明确电势能、电势、静电力的功、电势能的关系。了解电势与电场线的关系,了解等势面的意义及与电场线的关系。
复习提问:
1、什么是功?功的计算公式是什么?
功的定义:一个物体在力的作用下,如果沿力的方向发生了一段位移,那么该力就对物体做了功。
公式:W?F?lcos?
2、重力做功的大小有什么特点?
(1)与路径无关,由初末位置的高度差来决定;
(2)WG与重力势能EP的关系:WG?Ep1?EP2???EP
(3)重力势能是相对的,有零势能面(人为选定),重力势能具有系统性。 3、功与能之间有什么关系?
功和能的关系:功是能量转化的量度(做功的过程是一个能量转化的过程) 4、电场的基本性质是什么?把一个静止的试探电荷放入电场中,经过一时间后电荷会怎样?此过程中哪个力对谁做了功?
电场的基本性质是:电场能对放入其中的电荷产生力的作用。 静止的试探电荷放入电场中,它将在静电力的作用下做加速运动,经过一段时间后获得一定的速度,它的动能增加了。
此过程中,静电力对电荷做了功,使得电荷的动能增加了。 新课教学
那么,静电力做功有什么特点呢?
本节我们重点讨论试探电荷在匀强电场中时静电力做功的特点。 一、静电力做功的特点
如图,试探电荷在电场强度
BE为E的匀强电场中沿不同的路径
从A点移动到B点。
情形1:把q沿直线从A移往B。
+q 试探电荷q受到的静电力:MFA?F?qE
此过程静电力对试探电荷做的功:W?F?ABcos??qE?AM 情形2:把q沿折线AMB从A移往B。
Obviously, face China's Socialist system, the Communist Party is not the party. In that case, political chaos has been very tight. Is remodeling or reconstruction, is a correction or a stove. Whether to turn right or left, is back to the source or put forward new political ideas. This is to determine the road problems in China, is also the key out of the deep water of the reform of the economic system. After 18, the new Central collective leadership attaches great importance to political orientation. First, the \cles\ng point, starting from the Central Government's self-restraint, which preaches and pro-image, brought fresh feeling to the community. Secondly, before reform and opening up and reform and opening two periods after non-negative, untying the tangle of the society a long time on this issue. Third, a new generation of party leaders on various occasions to Mao Ze-Dong and Mao Ze-Dong's thought of evaluation has room for manoeuvre, through to the ruling ideology of Mao Zedong thought, is the call of the soul to the Socialist Revolution and construction. Empty talks jeopardize national interests and try again, is an affirmation of Deng Xiao-ping's reform ideas. These strong political signal showing a new generation of political leaders is still keeping to the Socialist road. Four is revisiting the \o Ze-Dong's historical cycle of\ofile anti-corruption and the importance of the Constitution, reorganization is bad style of officialdom, was to civilize people obey the law, while improving the color change of the regime of vigilance. Five is to reform into deeper waters and stressed that top-level design, this is a review on the reform and opening up in the past, is also looking for a way out. Six foreign and Russia closer, the flexible attitude on the issue of the Korean peninsula, Sino-Japanese fishing hardline China on the island out of the \nt\ow profile shadow began to gradually plan development. Signs show that the new leadership began to make a left turn in politics. However, as of right now, not only ideological confusion in the community, the new leadership's thinking is messy. New leaders both stressed the need to implement the Constitution, stressed the need to turn off the power in a cage. Also stresses that Mao Zedong thought cannot be lost, 30 years after the reform and opening up 30 years ago can not deny each other. Both advocate democracy and release \n does not speak of\cal constraints. Neither deny the history of the CPC Central Committee on several issues ...Comrades: today brings together members, mainly in order to provide a platform to Exchange and learn from each other in order to facilitate our work. Just now, we focus on taxation, planning and stability, safety, project construction, typical topics such as private facts presentation and interaction, and towns currently exist in the in-depth analysis of the problems to be solved, to explore new methods to solve the problem. It can be said that summing up the achievement, no grandstanding; analysispromotion of employment, form a reasonable and orderly pattern of income distribution, build a more fair and sustainable social security systems, medical and health system reform. The plenary, innovation of social governance, must focus on the maintenance of fundamental interests of the overwhelming majority of the people, maximize factors, enhance social development, improving social governance, the interests of national security, ensure that the people live and work, social stability and order. o improve social governance, stimulating social organization, innovative and effective system of preventing and resolving social conflicts, improving the public security system, set up the National Security Council, national security systems and national security strategy to ensure national security. Plenary session, the construction of ecological civilization, you must establish systems of ecological system, using the system to protect the ecological environment. o improve naturalresources asset property right system and use control, red line of delimitation of ecological protection, resources paid use system and ecological compensation system in ecological environment protection management system reform. Plenary session, centering on building a listening party command, can win and having a fine style of the people's army, a strong army under the new situation of the party Goals, restricting the development of national defense and army building is solved outstanding contradictions and problems, innovation and development of military theory, enhance military strategic guidance, improve the military strategy in the new period, building a modern military force system with Chinese characteristics. o deepen the adjustment of personnel system reform in the army, military policy and system reform, promote the development of military and civilian integration depth. Plenary session stressed that comprehensive reform must be to strengthen and improve theparty's leadership, give full play to the core role of the party commands the overall situation and coordinating all parties, improving the party's leading water ... Margin. Challenged the leadership of the Communist Party of China, Marxism-Leninism and Mao Zedong thought by Deng Xiao-ping's flag, replaced by three representatives and the harmonic society. The former Communist Party spirit and social cohesion point of almost all political makeover. Characteristics of socialism public ownership is shifting to private ownership, planned regulation and market regulation, the proletarian regime controlled by the elite. Of universal equality, fairness and basic principles of distribution system is socialist society, however after economic monopolized by powerful, vested interests growemployers do not have the same status, hardly seems fair social distribution. State key protection of capital interests rather than the interests of citizens, had been hits the bottom of the proletariat 在线段AM上静电力对q做的功W1?qE?AM 在线段MB上静电力对q做的功W2?0
在整个过程中静电力对q做的功W?W1?W2?qE?AM
情形3:把q沿任意曲线ANB从A移往B。
我们可以把曲线ANB分解成无数组与电场线平行和垂直的折线。(画图演示)
由情形2可知,电荷q沿平
B行于电场线方向移动时,静电力EN 做功,沿垂直电场线方向移动
时,静电力不做功。而这些与电场线平行的短折线长度之和等
+q AM于AM。故沿曲线ANB移动q静电力做的功:W?qE?AM
结论:在匀强电场中移动电荷时,静电力做的功与电荷的起始位置和终止
位置有关,但与电荷经过的路径无关。
可以证明,此结论也适用于非匀强电场。
思考:静电力做功的过程与什么力做功的过程有类似的特点?(重力做功) 在前面我们学过功和能的关系,功是能量转化的量度,做功的过程实质上就是一个能量转化的过程。在电场中移动电荷静电力会对电荷做功这一现象说明,在电场中的电荷具有能量。那么,静电力做功的过程是什么能转化为电荷的动能呢?
二、电势能
电荷在电场中具有的能量不仅与电场和电荷本身有关,还与电荷在电场中的位置有关,我们把:
电荷在电场中具有的与电荷位置有关的能,叫电势能。
电场力做功与电势能有什么关系?(联系重力做功与重力势能的关系) 物体被举高具有重力势能。 1、电荷在电场中具有电势能。
重力对物体做正功,物体的重力势能减小 2、电场力对电荷做正功,电荷的电势能减小 重力对物体做负功,物体的重力势能增大 3、电场力对电荷做负功,电荷的电势能增大
重力做多少功,物体重力势能就减少多少。WG?Ep1?Ep2???Ep 4、电场力做多少功,电荷电势能就减少多少。WAB?EpA?EpB???Ep 重力势能是相对的,与零势能面有关
Obviously, face China's Socialist system, the Communist Party is not the party. In that case, political chaos has been very tight. Is remodeling or reconstruction, is a correction or a stove. Whether to turn right or left, is back to the source or put forward new political ideas. This is to determine the road problems in China, is also the key out of the deep water of the reform of the economic system. After 18, the new Central collective leadership attaches great importance to political orientation. First, the \point, starting from the Central Government's self-restraint, which preaches and pro-image, brought fresh feeling to the community. Secondly, before reform and opening up and reform and opening two periods after non-negative, untying the tangle of the society a long time on this issue. Third, a new generation of party leaders on various occasions to Mao Ze-Dong and Mao Ze-Dong's thought of evaluation has room for manoeuvre, through to the ruling ideology of Mao Zedong thought, is the call of the soul to the Socialist Revolution and construction. Empty talks jeopardize national interests and try again, is an affirmation of Deng Xiao-ping's reform ideas. These strong political signal showing a new generation of political leaders is still keeping to the Socialist road. Four is revisiting the \ng to Mao Ze-Dong's historical cycle of\profile anti-corruption and the importance of the Constitution, reorganization is bad style of officialdom, was to civilize people obey the lawwhile improving the color change of the regime of vigilance. Five is to reform into deeper waters and stressed that top-level design, this is a review on the reform and opening up in the past, is also looking for a way out. Six foreign and Russia closer, the flexible attitude on the issue of the Korean peninsula, Sino-Japanese fishing hardline China on the island out of the \ent\ow profile shadow began to gradually plan development. Signs show that the new leadership began to make a left turn in politics. However, as of right now, not only ideological confusion in the community, the new leadership's thinking is messy. New leaders both stressed the need to implement the Constitution, stressed the need to turn off the power in a cage. Also stresses that Mao Zedong thought cannot be lost, 30 years after the reform and opening up 30 years ago can not deny each other. Both advocate democracy and release \n does not speak of\cal constraints. Neither deny the history of the CPC Central Committee on several issues ...
Comrades: today brings together members, mainly in order to provide a platform to Exchange and learn from each other in order to facilitate our work. Just now, we focus on taxation, planning and stability, safety, project construction, typical topics such as private facts presentation and interaction, and towns currently exist in the in-depth analysis of the problems to be solved, to explore new methods to solve the problem. It can be said that summing up the achievement, no grandstanding; analysis2
promotion of employment, form a reasonable and orderly pattern of income distribution, build a more fair and sustainable social security systems, medical and health system reform. The plenary, innovation of social governance, must focus on the maintenance of fundamental interests of the overwhelming majority of the people, maximize factors, enhance social development, improving social governance, the interests of national security, ensure that the people live and work, social stability and order. o improve social governance, stimulating social organization, innovative and effective system of preventing and resolving social conflicts, improving the public security system, set up the National Security Council, national security systems and national security strategy to ensure national security. Plenary session, the construction of ecological civilization, you must establish systems of ecological system, using the system to protect the ecological environmnt. o improve naturalresources asset property right system and use control, red line of delimitation of ecological protection, resources paid use system and ecological compensation system in ecological environment protection management system reform. Plenary session, centering on building a listening party command, can win and having a fine style of the people's army, a strong army under the new situation of the party Goals, restricting the development of national defense and army building is solved outstanding contradictions and problems, innovation and development of military theory, enhance military strategic guidance, improve the military strategy in the new period, building a modern military force system with Chinese characteristics. o deepen the adjustment of personnel system reform in the army, military policy and system reform, promote the development of military and civilian integration depth. Plenary session stressed that comprehensive reform must be to strengthen and improve theparty's leadership, give full play to the core role of the party commands the overall situation and coordinating all parties, improving the party's leading water ... Margin. Challenged the leadership of the Communist Party of China, Marxism-Leninism and Mao Zedong thought by Deng Xiao-ping's flag, replaced by three representatives and the harmonic society. The former Communist Party spirit and social cohesion point of almost all political makeover. Characteristics of socialism public ownership is shifting to private ownership, planned regulation and market regulation, the proletarian regime controlled by the elite. Of universal equality, fairness and basic principles of distribution system is socialist society, however after economic monopolized by powerful, vested interests growemployers do not have the same status, hardly seems fair social distribution. State key protection of capital interests rather than the interests of citizens, had been hits the bottom of the proletariat 5、电势能是相对的,与零电势能面有关
通常把电荷在离场源电荷无限远处的电势能规定为零,或把电荷在大地表面上电势能规定为零。
电荷在某点的电势能,等于静电力把它从该处移动到零势能位置所做的功(正电荷在电场中的电势能为正值,负电荷在电场中的电势能为负值)
重力势能是物体和地球所共有的,具有系统性 6、电势能是电荷和电场所共有的,具有系统性 重力势能是标量。 7、电势能是标量
尽管重力做功与电场力做功很相似,但它们之间还是存在着一些差别。 静电力做功的电荷有两种——正电荷和负电荷;而重力做功的物体只有一种。
正电荷沿电场线移动, 电场力做正功,电势能减少 负电荷沿电场线移动, 电场力做负功,电势能增加 正电荷逆电场线移动, 电场力做负功,电势能增加 负电荷逆电场线移动, 电场力做正功,电势能减少
例1.图中MN为电场中某一条电场线方向向右,在线上取两点a、b, 现将一电荷+q从a移到b则( C ) A.电场力做正功,+q的电势能增加; B.电场力做负功,+q的电势能增加; C.电场力做正功,+q的电势能减少; D.电场力做负功,+q的电势能减少。
例2:A和B为电场中某条电场线上的点,如图:将q?4?10?9C的正电荷从A点移到B点需克服电场力做功5 ×10-7J,则 (1)电场方向由A→B还是B→A? (2)电荷在哪点时电势能大?大多少?
AB 在上一节,通过静电力的研究认识了电场强度E,我们用电场强度E来表示电场的力的性质。在这一节,我们研究电势能,那么电场的能的性质我们又应该用什么物理量来描述呢?能否用“电势能”呢?
电场的能的性质也是电场本身的一种属性,它只能由场源本身所决定,而与电场中有无放入试探电荷无关。而电势能的大小是与试探电荷的电量q有关的(因q越大,其所受电场力就越大,具有的做功本领大,电势能也就大),故不能用“电势能”来描述电场的能的性质,我们引入一个新的物理量——“电势”来表
Obviously, face China's Socialist system, the Communist Party is not the party. In that case, political chaos has been very tight. Is remodeling or reconstruction, is a correction or a stove. Whether to turn right or left, is back to the source or put forward new political ideas. This is to determine the road problems in China, is also the key out of the deep water of the reform of the economic system. After 18, the new Central collective leadership attaches great importance to political orientation. First, the \point, starting from the Central Government's self-restraint, which preaches and pro-image, brought fresh feeling to the community. Secondly, before reform and opening up and reform and opening two periods after non-negative, untying the tangle of the society a long time on this issue. Third, a new generation of party leaders on various occasions to Mao Ze-Dong and Mao Ze-Dong's thought of evaluation has room for manoeuvre, through to the ruling ideology of Mao Zedong thought, is the call of the soul to the Socialist Revolution and construction. Empty talks jeopardize national interests and try again, is an affirmation of Deng Xiao-ping's reform ideas. These strong political signal showing a new generation of political leaders is still keeping to the Socialist road. Four is revisiting the \ng to Mao Ze-Dong's historical cycle of\profile anti-corruption and the importance of the Constitution, reorganization is bad style of officialdom, was to civilize people obey the law, while improving the color change of the regime of vigilance. Five is to reform into deeper waters and stressed that top-level design, this is a review on the reform and opening up in the past, is also looking for a way out. Six foreign and Russia closer, the flexible attitude on the issue of the Korean peninsula, Sino-Japanese fishing hardline China on the island out of the \ent\ow profile shadow began to gradually plan development. Signs show that the new leadership began to make a left turn in politics. However, as of right now, not only ideological confusion in the community, the new leadership's thinking is messy. New leaders both stressed the need to implement the Constitution, stressed the need to turn off the power in a cage. Also stresses that Mao Zedong thought cannot be lost, 30 years after the reform and opening up 30 years ago can not deny each other. Both advocate democracy and release \n does not speak of\cal constraints. Neither deny the history of the CPC Central Committee on several issues ...
Comrades: today brings together members, mainly in order to provide a platform to Exchange and learn from each other in order to facilitate our work. Just now, we focus on taxation, planning and stability, safety, project construction, typical topics such as private facts presentation and interaction, and towns currently exist in the in-depth analysis of the problems to be solved, to explore new methods to solve the problem. It can be said that summing up the achievement, no grandstanding; analysis3
promotion of employment, form a reasonable and orderly pattern of income distribution, build a more fair and sustainable social security systems, medical and health system reform. The plenary, innovation of social governance, must focus on the maintenance of fundamental interests of the overwhelming majority of the people, maximize factors, enhance social development, improving social governance, the interests of national security, ensure that the people live and work, social stability and order. o improve social governance, stimulating social organization, innovative and effective system of preventing and resolving social conflicts, improving the public security system, set up the National Security Council, national security systems and national security strategy to ensure national security. Plenary session, the construction of ecological civilization, you must establish systems of ecological system, using the system to protect the ecological environment. o improve naturalresources asset property right system and use control, red line of delimitation of ecological protection, resources paid use system and ecological compensation system in ecological environment protection management system reform. Plenary session, centering on building a listening party command, can win and having a fine style of the people's army, a strong army under the new situation of the party Goals, restricting the development of national defense and army building is solved outstanding contradictions and problems, innovation and development of military theory, enhance military strategic guidance, improve the military strategy in the new period, building a modern military force system with Chinese characteristics. o deepen the adjustment of personnel system reform in the army, military policy and system reform, promote the development of military and civilian integration depth. Plenary session stressed that comprehensive reform must be to strengthen and improve theparty's leadership, give full play to the core role of the party commands the overall situation and coordinating all parties, improving the party's leading water ... Margin. Challenged the leadership of the Communist Party of China, Marxism-Leninism and Mao Zedong thought by Deng Xiao-ping's flag, replaced by three representatives and the harmonic society. The former Communist Party spirit and social cohesion point of almost all political makeover. Characteristics of socialism public ownership is shifting to private ownership, planned regulation and market regulation, the proletarian regime controlled by the elite. Of universal equality, fairness and basic principles of distribution system is socialist society, however after economic monopolized by powerful, vested interests growemployers do not have the same status, hardly seems fair social distribution. State key protection of capital interests rather than the interests of citizens, had been hits the bottom of the proletariat 示它。
三、电势
1、电势是描述电场能的性质的物理量。
那么,怎样描述电场能的性质、如何定义电势呢? 我们已经熟悉了用比值定义物理量的方法,现在就来研究电荷在电场中的电势能与它电荷量的比值,从这里入手来研究电势。
如图所示,在场强为E的匀强电场中, O点为零势能位置,A为匀强电场中任意一点。
则电荷q在A点的电势能等于把电荷q从A移至O静电力做的功:
A lE
EpA?qElcos?
?o由上式可知,电荷在任意一点的电势能与它的电荷量成正比。
电荷q在A点的电势能与电荷量q之比为:
EpAq?Elcos?
由上式可知,在电场中的A点,无论电荷的电荷量是多少,电荷是正还是负,电势能与电荷量q之比
EpAq是相同的,而在电场中的不同位置,由于l和?可能不同,这个比值一般是不同的。
结论:电荷在电场中某点的电势能与它电荷量之比,是由电场中这点的性质决定的,与试探电荷本身无关。该结论不仅适用于匀强电场,同样也适用于其他电场。
在物理学中,电荷在电场中某一点的电势能与它的电荷量的比值,叫做这一点的电势。(电势用符号?表示)
2、电势:电荷在电场中某一点的电势能与它的电荷量的比值 3、公式:??Epq
V?1J/C 4、单位:伏特(V)1物理意义:在电场中的某点,如果电荷量为1C的电荷在该点的电势能为1J,那么该点的电势为1V。
ABE
如图,将一正试探电荷从A沿电场线移向B,它的电势能将如何变化?它
Obviously, face China's Socialist system, the Communist Party is not the party. In that case, political chaos has been very tight. Is remodeling or reconstruction, is a correction or a stove. Whether to turn right or left, is back to the source or put forward new political ideas. This is to determine the road problems in China, is also the key out of the deep water of the reform of the economic system. After 18, the new Central collective leadership attaches great importance to political orientation. First, the \point, starting from the Central Government's self-restraint, which preaches and pro-image, brought fresh feeling to the community. Secondly, before reform and opening up and reform and opening two periods after non-negative, untying the tangle of the society a long time on this issue. Third, a new generation of party leaders on various occasions to Mao Ze-Dong and Mao Ze-Dong's thought of evaluation has room for manoeuvre, through to the ruling ideology of Mao Zedong thought, is the call of the soul to the Socialist Revolution and construction. Empty talks jeopardize national interests and try again, is an affirmation of Deng Xiao-ping's reform ideas. These strong political signal showing a new generation of political leaders is still keeping to the Socialist road. Four is revisiting the \ng to Mao Ze-Dong's historical cycle of\profile anti-corruption and the importance of the Constitution, reorganization is bad style of officialdom, was to civilize people obey the lawwhile improving the color change of the regime of vigilance. Five is to reform into deeper waters and stressed that top-level design, this is a review on the reform and opening up in the past, is also looking for a way out. Six foreign and Russia closer, the flexible attitude on the issue of the Korean peninsula, Sino-Japanese fishing hardline China on the island out of the \ent\ow profile shadow began to gradually plan development. Signs show that the new leadership began to make a left turn in politics. However, as of right now, not only ideological confusion in the community, the new leadership's thinking is messy. New leaders both stressed the need to implement the Constitution, stressed the need to turn off the power in a cage. Also stresses that Mao Zedong thought cannot be lost, 30 years after the reform and opening up 30 years ago can not deny each other. Both advocate democracy and release \n does not speak of\cal constraints. Neither deny the history of the CPC Central Committee on several issues ...
Comrades: today brings together members, mainly in order to provide a platform to Exchange and learn from each other in order to facilitate our work. Just now, we focus on taxation, planning and stability, safety, project construction, typical topics such as private facts presentation and interaction, and towns currently exist in the in-depth analysis of the problems to be solved, to explore new methods to solve the problem. It can be said that summing up the achievement, no grandstanding; analysis4
promotion of employment, form a reasonable and orderly pattern of income distribution, build a more fair and sustainable social security systems, medical and health system reform. The plenary, innovation of social governance, must focus on the maintenance of fundamental interests of the overwhelming majority of the people, maximize factors, enhance social development, improving social governance, the interests of national security, ensure that the people live and work, social stability and order. o improve social governance, stimulating social organization, innovative and effective system of preventing and resolving social conflicts, improving the public security system, set up the National Security Council, national security systems and national security strategy to ensure national security. Plenary session, the construction of ecological civilization, you must establish systems of ecological system, using the system to protect the ecological environmnt. o improve naturalresources asset property right system and use control, red line of delimitation of ecological protection, resources paid use system and ecological compensation system in ecological environment protection management system reform. Plenary session, centering on building a listening party command, can win and having a fine style of the people's army, a strong army under the new situation of the party Goals, restricting the development of national defense and army building is solved outstanding contradictions and problems, innovation and development of military theory, enhance military strategic guidance, improve the military strategy in the new period, building a modern military force system with Chinese characteristics. o deepen the adjustment of personnel system reform in the army, military policy and system reform, promote the development of military and civilian integration depth. Plenary session stressed that comprehensive reform must be to strengthen and improve theparty's leadership, give full play to the core role of the party commands the overall situation and coordinating all parties, improving the party's leading water ... Margin. Challenged the leadership of the Communist Party of China, Marxism-Leninism and Mao Zedong thought by Deng Xiao-ping's flag, replaced by three representatives and the harmonic society. The former Communist Party spirit and social cohesion point of almost all political makeover. Characteristics of socialism public ownership is shifting to private ownership, planned regulation and market regulation, the proletarian regime controlled by the elite. Of universal equality, fairness and basic principles of distribution system is socialist society, however after economic monopolized by powerful, vested interests growemployers do not have the same status, hardly seems fair social distribution. State key protection of capital interests rather than the interests of citizens, had been hits the bottom of the proletariat 的电势是如何变化的?如果将一负试探电荷从A沿电场线移向B呢?
5、电势的特点
(1)沿着电场线的方向电势逐渐降低。 (2)某点电势的大小是相对于电势零点而言的。电势零点的选择是任意的,一般选地面和无穷远为电势零点。
(3)规定了电势零点之后,比电势零点电势高的电势取正值,比电势零点低的电势取负值。
(4)电势是标量。计算时q、Ep、?都要带正负号。 例题习题略
四、等势面
在地图中常用等高线来表示地势的高低。与此相似,在电场的图示中常用等势面来表示电势的高低。
1、等势面:电场中电势相同的各点构成的面。 2、等势面的特点:
(1)等势面一定跟电场线垂直,在同一等势面上的任意两点间移动电荷,电场力不做功;
(2)电场线总是从电势高的等势面指向电势低的等势面,任意两个等势面都不会相交;
(3)等差等势面越密的地方电场强度越大 3、几种带电体周围的等势面和电场线
例题习题略
课堂小结
一、静电力做功的特点
Obviously, face China's Socialist system, the Communist Party is not the party. In that case, political chaos has been very tight. Is remodeling or reconstruction, is a correction or a stove. Whether to turn right or left, is back to the source or put forward new political ideas. This is to determine the road problems in China, is also the key out of the deep water of the reform of the economic system. After 18, the new Central collective leadership attaches great importance to political orientation. First, the \point, starting from the Central Government's self-restraint, which preaches and pro-image, brought fresh feeling to the community. Secondly, before reform and opening up and reform and opening two periods after non-negative, untying the tangle of the society a long time on this issue. Third, a new generation of party leaders on various occasions to Mao Ze-Dong and Mao Ze-Dong's thought of evaluation has room for manoeuvre, through to the ruling ideology of Mao Zedong thought, is the call of the soul to the Socialist Revolution and construction. Empty talks jeopardize national interests and try again, is an affirmation of Deng Xiao-ping's reform ideas. These strong political signal showing a new generation of political leaders is still keeping to the Socialist road. Four is revisiting the \ng to Mao Ze-Dong's historical cycle of\profile anti-corruption and the importance of the Constitution, reorganization is bad style of officialdom, was to civilize people obey the law, while improving the color change of the regime of vigilance. Five is to reform into deeper waters and stressed that top-level design, this is a review on the reform and opening up in the past, is also looking for a way out. Six foreign and Russia closer, the flexible attitude on the issue of the Korean peninsula, Sino-Japanese fishing hardline China on the island out of the \ent\ow profile shadow began to gradually plan development. Signs show that the new leadership began to make a left turn in politics. However, as of right now, not only ideological confusion in the community, the new leadership's thinking is messy. New leaders both stressed the need to implement the Constitution, stressed the need to turn off the power in a cage. Also stresses that Mao Zedong thought cannot be lost, 30 years after the reform and opening up 30 years ago can not deny each other. Both advocate democracy and release \n does not speak of\cal constraints. Neither deny the history of the CPC Central Committee on several issues ...
Comrades: today brings together members, mainly in order to provide a platform to Exchange and learn from each other in order to facilitate our work. Just now, we focus on taxation, planning and stability, safety, project construction, typical topics such as private facts presentation and interaction, and towns currently exist in the in-depth analysis of the problems to be solved, to explore new methods to solve the problem. It can be said that summing up the achievement, no grandstanding; analysis5