高中物理第一章靜電場(chǎng)第4節(jié)電勢(shì)能電勢(shì)與電勢(shì)差省公開課一等獎(jiǎng)新名師獲獎(jiǎng)?wù)n件

1/522/523/52電勢(shì)能重力勢(shì)能系統(tǒng)電荷和_____物體和_____大小相對(duì)性電荷在某點(diǎn)電勢(shì)能等于把電荷從該點(diǎn)移到零勢(shì)能位置時(shí)________做功物體在某點(diǎn)重力勢(shì)能等于把物體從該點(diǎn)移到零勢(shì)能位置時(shí)_____做功改變大小量度靜電力功是電勢(shì)能改變大小量度，靜電力做功等于______降低許重力功是重力勢(shì)能改變大小量度，重力做功等于_________降低許對(duì)應(yīng)力做功特點(diǎn)做功多少只與始、末位置相關(guān)，與經(jīng)過_____無關(guān)，且功等于勢(shì)能_____量4/525/526/527/528/529/5210/5211/5212/5213/5214/5215/52做功判定法不論是哪種電荷，只要電場(chǎng)力做正功，電荷電勢(shì)能一定降低；只要電場(chǎng)力做負(fù)功，電荷電勢(shì)能一定增加。電場(chǎng)線法正電荷順著電場(chǎng)線方向移動(dòng)，電勢(shì)能一定減小，逆著電場(chǎng)線方向移動(dòng)，電勢(shì)能一定增加；負(fù)電荷順著電場(chǎng)線方向移動(dòng)，電勢(shì)能一定增加，逆著電場(chǎng)線方向移動(dòng)，電勢(shì)能一定減小。電性判定法同種電荷靠近時(shí)電勢(shì)能增大，遠(yuǎn)離時(shí)電勢(shì)能減??；異種電荷靠近時(shí)電勢(shì)能減小，遠(yuǎn)離時(shí)電勢(shì)能增大。16/5217/5218/5219/5220/5221/5222/5223/52聯(lián)絡(luò)焦耳J伏特V單位正點(diǎn)電荷(＋q)：電勢(shì)能正負(fù)跟電勢(shì)正負(fù)相同負(fù)點(diǎn)電荷(－q)：電勢(shì)能正負(fù)跟電勢(shì)正負(fù)相反電勢(shì)沿電場(chǎng)線逐步降低，要求零電勢(shì)點(diǎn)后，某點(diǎn)電勢(shì)高于零，則為正值；某點(diǎn)電勢(shì)低于零，則為負(fù)值大小電勢(shì)能大小是由點(diǎn)電荷q和該點(diǎn)電勢(shì)φ共同決定電場(chǎng)中某一點(diǎn)電勢(shì)φ大小，只跟電場(chǎng)本身相關(guān)，跟點(diǎn)電荷q無關(guān)相關(guān)原因反應(yīng)電荷在電場(chǎng)中某點(diǎn)所含有能量反應(yīng)電場(chǎng)能性質(zhì)物理量物理意義電勢(shì)能Ep電勢(shì)φ24/5225/5226/52判斷角度判斷方法場(chǎng)源電荷正負(fù)法取無窮遠(yuǎn)處電勢(shì)為零，正電荷周圍電勢(shì)為正值，負(fù)電荷周圍電勢(shì)為負(fù)值；靠近正電荷處電勢(shì)高，靠近負(fù)電荷處電勢(shì)低電場(chǎng)線方向法沿著電場(chǎng)線方向電勢(shì)逐步降低；逆著電場(chǎng)線方向電勢(shì)逐步升高電場(chǎng)力做功法電場(chǎng)力做正功，電勢(shì)能降低，若為正電荷，電勢(shì)降低；若為負(fù)電荷，電勢(shì)升高。電場(chǎng)力做負(fù)功，電勢(shì)能增加，若為正電荷，電勢(shì)升高；若為負(fù)電荷，電勢(shì)降低電勢(shì)能高低法正電荷電勢(shì)能大處電勢(shì)高，負(fù)電荷電勢(shì)能大處電勢(shì)低27/5228/5229/5230/5231/5232/5233/52電勢(shì)相等降低與連線交點(diǎn)處最高中點(diǎn)處最低兩等量正電荷連線上和中垂線上關(guān)于中點(diǎn)對(duì)稱點(diǎn)從中點(diǎn)沿中垂線向兩側(cè)連線中垂線上連線上34/52中垂線上電勢(shì)相等，連線上與中點(diǎn)電勢(shì)差絕對(duì)值相等，且一正一負(fù)不變中垂線為等勢(shì)線從正電荷向負(fù)電荷降低兩等量異種電荷電勢(shì)相等升高與連線交點(diǎn)處最低中點(diǎn)處最高兩等量負(fù)電荷連線上和中垂線上關(guān)于中點(diǎn)對(duì)稱點(diǎn)從中點(diǎn)沿中垂線向兩側(cè)連線中垂線上連線上35/5236/5237/5238/5239/5240/5241/5