高中物理电势能和电势 教案

高中 高中语文新课程标准高中物理选修31全套教案高中英语研修观课报告高中物理学习方法和技巧高中数学说课稿范文 物理电势能和电势 教案 电势能和电势 倘若把一个静止的试探电荷放入电场中，他将在静电力的作用下作加速运动，经过一段时间后获得一定的速度，试探电荷的动能增加了。我们知道，这是静电力做功的结果，而功又是能转化的量度，那么，在这一过程中，是什么能转化为试探电荷的动能,这个能具有什么特点,它还可以引申出与它紧密相关哪些物理量,这些物理量具有怎样的性质,这就是本节课我们要讨论的问题。(板书:电势能和电势) 一、静电力做功的特点 让试探电荷q在电场强度为E的匀强电场中沿几条不同路径从A点运动到B点，我们来计算这几种情况下静电力对电荷所做的功。 W,F|AB|,qE|AB| W,F|AB|cosθ,qE|AM| W,W+W+W+„ 123 ,其中F,qE，结果都一样即:W=qEL=qE|AB|cos AM 结论:静电力做的功只与电荷的起始位置和终点位置有关，与电荷经过的路径无关。 二、电势能 of 3 JB/ T4735-1997 steel welded atmospheric pressure vessel 4 GB50231-2009 mechanical equipment installation engineering construction and acceptance specification for 5 GB50275-98 compressor, fan and pump installation engineering construction and acceptance specification for lifting 6 HG20201-2000 construction installation engineering construction standard 7, HG ... Pressure gauges, using an installed spark arrestor for acetylene cylinders, illegal carrying, using gas cylinders, each operator fined 20 Yuan. Gas bottle without the hot sun exposure measures, responsibilities of team a fine of 50 Yuan. (7) at height and the opening and provisional protective measures have been taken, the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 1~2 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury accident occurred, the direct punishment 0.5-10,000 yuan, responsible for the direct responsibility for the accident and the responsibility of leadership, such as concerning administrative sanctions should be dealt with by the personnel Department of the company. (3) personal injury accident occurs, the direct punishment 500-1000, who is directly responsible for the accident responsibility, give notice of criticism and 50-100 economic sanctions against them. (4) to conceal the accident, reported without undue delay or false, to inform the administrative leadership of the criticism, resulting in serious 力做功只与物体位置有关，而与运动路径无关的事例在物理中有哪些呢,(移动物体时重力做的功与路径无关) 特征或性 静电场 重力场 质 对场中的电荷有力的对场中的物体有力的 a 作用 作用 用比值“F/q” 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 示场用比值“F/m”表示场 b 的强弱 的强弱 可见，静电场与重力场有某些特征是相似的。同一物体在地面附近的同一位置具有确定的重力势能。静电力做功也与路径无关，那是否也就能建立电势能的概念呢, 1.电势能:由于移动电荷时静电力做功与移动的路径无关，电荷在电场中也具有势能，这种势能我们叫做电势能。电势能用E表示。 p2.讨论:静电力做功与电势能变化的关系 重力做的正功等于减少的重力势能，克服重力做的功等于增加的重力势能，用公式表示为W,E,E,,ΔE。那么静电力做的正功ABpApBp 也等于减少的电势能吗,克服静电力做的功也等于增加的电势能吗,用公式表示也是W,E,E,,ΔE吗, ABpApBp 根据动能定理，W,E,E,ΔEk。因为，根据能量守恒增加的动能ABkBkA 等于减少的电势能，E,E,E,E，所以W,E,E,,Δ。 kBkApApBABpApBEpof 3 JB/ T4735-1997 steel welded atmospheric pressure vessel 4 GB50231-2009 mechanical equipment installation engineering construction and acceptance specification for 5 GB50275-98 compressor, fan and pump installation engineering construction and acceptance specification for lifting 6 HG20201-2000 construction installation engineering construction standard 7, HG ... Pressure gauges, using an installed spark arrestor for acetylene cylinders, illegal carrying, using gas cylinders, each operator fined 20 Yuan. Gas bottle without the hot sun exposure measures, responsibilities of team a fine of 50 Yuan. (7) at height and the opening and provisional protective measures have been taken, the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 1~2 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury accident occurred, the direct punishment 0.5-10,000 yuan, responsible for the direct responsibility for the accident and the responsibility of leadership, such as concerning administrative sanctions should be dealt with by the personnel Department of the company. (3) personal injury accident occurs, the direct punishment 500-1000, who is directly responsible for the accident responsibility, give notice of criticism and 50-100 economic sanctions against them. (4) to conceal the accident, reported without undue delay or false, to inform the administrative leadership of the criticism, resulting in serious 静电力做的功等于电势能的变化。电场力做多少功，电势能就变化多少，在只受电场力作用下，电势能与动能相互转化，而他们总量保持不变。 对不同的电荷从A运动到B的过程中，电势能的变化情况: 正电荷从A运动到B做正功，即有W>0，则E>E，电势能减少。 ABpApB ?正电荷顺着电场线的方向其电势能逐渐减少。 负电荷从A运动到B做正功，即有W<0，则E>E，电势能增加。 ABpApB ?负电荷顺着电场线的方向其电势能逐渐降低。 (正电荷顺着电场线移动，电场力做正功，电势能减少;正电荷逆着电场线移动，电场力做负功，电势能增加;负电荷顺着电场线移动，电场力做负功，电势能增加;负电荷逆着电场线移动，电场力做正功，电势能减少) 3(求电荷在某点处具有的电势能 在上面讨论的问题中，请分析求出A点的电势能为多少,学生思考后无法直接求出，不妨就此激励学生，并提出类比方法。那么如何求出A点的重力势能呢, of 3 JB/ T4735-1997 steel welded atmospheric pressure vessel 4 GB50231-2009 mechanical equipment installation engineering construction and acceptance specification for 5 GB50275-98 compressor, fan and pump installation engineering construction and acceptance specification for lifting 6 HG20201-2000 construction installation engineering construction standard 7, HG ... Pressure gauges, using an installed spark arrestor for acetylene cylinders, illegal carrying, using gas cylinders, each operator fined 20 Yuan. Gas bottle without the hot sun exposure measures, responsibilities of team a fine of 50 Yuan. (7) at height and the opening and provisional protective measures have been taken, the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 1~2 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury accident occurred, the direct punishment 0.5-10,000 yuan, responsible for the direct responsibility for the accident and the responsibility of leadership, such as concerning administrative sanctions should be dealt with by the personnel Department of the company. (3) personal injury accident occurs, the direct punishment 500-1000, who is directly responsible for the accident responsibility, give notice of criticism and 50-100 economic sanctions against them. (4) to conceal the accident, reported without undue delay or false, to inform the administrative leadership of the criticism, resulting in serious 则 E,W (以B为电势能零点) pAAB 电荷在某点的电势能，等于静电力把它从该点移动到零势能位置撕所做的功。 注意:通常把电荷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的电势能规定为零。 拓展:求电荷在电场中A、B两点具有的电势能高低。 将电荷由A点移动到B点，根据静电力做功情况判断。 若静电力做功为正功，电势能减少，电荷在A点电势能大于在B点的电势能。反之静 电力做负功，电势能增加，电荷在A点电势能小于在B点的电势能。弄清正、负电荷在电场中电势能的不同特点，判断其做功特点再进行判断。 三、电势 of 3 JB/ T4735-1997 steel welded atmospheric pressure vessel 4 GB50231-2009 mechanical equipment installation engineering construction and acceptance specification for 5 GB50275-98 compressor, fan and pump installation engineering construction and acceptance specification for lifting 6 HG20201-2000 construction installation engineering construction standard 7, HG ... Pressure gauges, using an installed spark arrestor for acetylene cylinders, illegal carrying, using gas cylinders, each operator fined 20 Yuan. Gas bottle without the hot sun exposure measures, responsibilities of team a fine of 50 Yuan. (7) at height and the opening and provisional protective measures have been taken, the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 1~2 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury accident occurred, the direct punishment 0.5-10,000 yuan, responsible for the direct responsibility for the accident and the responsibility of leadership, such as concerning administrative sanctions should be dealt with by the personnel Department of the company. (3) personal injury accident occurs, the direct punishment 500-1000, who is directly responsible for the accident responsibility, give notice of criticism and 50-100 economic sanctions against them. (4) to conceal the accident, reported without undue delay or false, to inform the administrative leadership of the criticism, resulting in serious 我们通过静电力的研究认识了电场强度，现在要通过电势能的研究来认识另一个物理量??电势。它同样是表征电场性质的重要物理量度。 通过类比可见，若用左图中的E/m，或右图中的E/q，它们的值是相pp 同的。如何来表征这个相同的量呢,(比值定义) 上面讨论的是特殊情况，下面我们来讨论一般情况:(如图) E,qELcosθ pA场 可见，E与q成正比，即电势能跟电荷量的比值E/q都是相同pApA的。对电场中不同位置，由于L与θ可以不同，所以这个比值一般是不同的。 电荷在电场中某一点的电势能与它的电荷量的比值，是由电场中这点的位置决定的，跟试探电荷本身无关。 of 3 JB/ T4735-1997 steel welded atmospheric pressure vessel 4 GB50231-2009 mechanical equipment installation engineering construction and acceptance specification for 5 GB50275-98 compressor, fan and pump installation engineering construction and acceptance specification for lifting 6 HG20201-2000 construction installation engineering construction standard 7, HG ... Pressure gauges, using an installed spark arrestor for acetylene cylinders, illegal carrying, using gas cylinders, each operator fined 20 Yuan. Gas bottle without the hot sun exposure measures, responsibilities of team a fine of 50 Yuan. (7) at height and the opening and provisional protective measures have been taken, the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 1~2 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury accident occurred, the direct punishment 0.5-10,000 yuan, responsible for the direct responsibility for the accident and the responsibility of leadership, such as concerning administrative sanctions should be dealt with by the personnel Department of the company. (3) personal injury accident occurs, the direct punishment 500-1000, who is directly responsible for the accident responsibility, give notice of criticism and 50-100 economic sanctions against them. (4) to conceal the accident, reported without undue delay or false, to inform the administrative leadership of the criticism, resulting in serious 得出结论后，引导学生类比电场的得来过程，提出新的物理量??电势。 1(定义:电荷在电场中某一点的电势能与他的电荷量的比值，叫做这一点的电势。用φ表示。 表达式:φ,E/q (与试探电荷无关) p 2(电势是标量，它只有大小没有方向，但有正负。 3(单位:伏特(V) 1V,1J/C 物理意义:电荷量为1C的电荷在该点的电势能是1J，则该点的电势就是1V。 4(电场线指向电势降低的方向。 电势顺线降低;顺着电场线方向，电势越来越低。与电势能相似，我们知道E有零势能面，因此电势也具有相对性。引导学生得出:应该p 先规定电场中某处的电势为零，然后才能确定电场中其他各点的电势。 5(零电势位置的规定:电场中某一点的电势的数值与零电势的选择有关，即电势的数值决定于零电势的选择。因此电势有正负之分，是由于其零电势的选择决定。通常以大地或无穷远默认为零。 特征或性 重力场 静电场 质 of 3 JB/ T4735-1997 steel welded atmospheric pressure vessel 4 GB50231-2009 mechanical equipment installation engineering construction and acceptance specification for 5 GB50275-98 compressor, fan and pump installation engineering construction and acceptance specification for lifting 6 HG20201-2000 construction installation engineering construction standard 7, HG ... Pressure gauges, using an installed spark arrestor for acetylene cylinders, illegal carrying, using gas cylinders, each operator fined 20 Yuan. Gas bottle without the hot sun exposure measures, responsibilities of team a fine of 50 Yuan. (7) at height and the opening and provisional protective measures have been taken, the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 1~2 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury accident occurred, the direct punishment 0.5-10,000 yuan, responsible for the direct responsibility for the accident and the responsibility of leadership, such as concerning administrative sanctions should be dealt with by the personnel Department of the company. (3) personal injury accident occurs, the direct punishment 500-1000, who is directly responsible for the accident responsibility, give notice of criticism and 50-100 economic sanctions against them. (4) to conceal the accident, reported without undue delay or false, to inform the administrative leadership of the criticism, resulting in serious 对场中的物体有引力的对场中的电荷有电场a 作用 力的作用 用比值“F/m”表示场的用比值“F/q”表示场b 强弱 的强弱 静电力做功与路径无c 重力做功与路径无关 关 重物在重力场中有重力电荷在电场中有电势d 势能 能 静电力做的正功等于 重力做的正功等于减少 减少的电势能，克服静 的重力势能，克服重力 电力做的功等于增加e 做的功等于增加的重力 的电势能，用公式表示 势能，用公式表示为WAB ,E,E,,Δ是WABpApB ,E,E,,ΔE。 pApBp E pf 重力势能具有相对性 电势能具有相对性 质点在某点的重力势能电荷在某点的电势能 等于把它从该点移动到等于把它从该点移动g 零势能处的过程中重力到零势能处的过程中 做的功 静电力做的功 重力势能属于物体 电势能属于电荷 h 与重力场组成的系统 与静电场组成的系统 of 3 JB/ T4735-1997 steel welded atmospheric pressure vessel 4 GB50231-2009 mechanical equipment installation engineering construction and acceptance specification for 5 GB50275-98 compressor, fan and pump installation engineering construction and acceptance specification for lifting 6 HG20201-2000 construction installation engineering construction standard 7, HG ... Pressure gauges, using an installed spark arrestor for acetylene cylinders, illegal carrying, using gas cylinders, each operator fined 20 Yuan. Gas bottle without the hot sun exposure measures, responsibilities of team a fine of 50 Yuan. (7) at height and the opening and provisional protective measures have been taken, the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 1~2 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury accident occurred, the direct punishment 0.5-10,000 yuan, responsible for the direct responsibility for the accident and the responsibility of leadership, such as concerning administrative sanctions should be dealt with by the personnel Department of the company. (3) personal injury accident occurs, the direct punishment 500-1000, who is directly responsible for the accident responsibility, give notice of criticism and 50-100 economic sanctions against them. (4) to conceal the accident, reported without undue delay or false, to inform the administrative leadership of the criticism, resulting in serious