大學(xué)物理-保守力與非保守力省公開(kāi)課金獎(jiǎng)全國(guó)賽課一等獎(jiǎng)微課獲獎(jiǎng)?wù)n件

一萬(wàn)有引力和彈性力作功特點(diǎn)(Thefeaturesoftheworkdonebytheuniversalgravitational&theelasticforce)

m’對(duì)m萬(wàn)有引力為m移動(dòng)dr時(shí),F作元功為1、萬(wàn)有引力作功(Workdonebyuniversalgravitationalforce)11/12m

從A到B過(guò)程中F作功：22/122、彈性力作功(Workdonebyelasticforce)彈性力x2x1xFOdxdW33/12保守力所作功僅決定于物體始、末位置,而與所經(jīng)過(guò)路徑無(wú)關(guān)．二保守力與非保守力保守力作功數(shù)學(xué)表示式(Theconservativeforce&Thenon-conservativeforceThemathematicalexpressionofworkbytheconservatiiveforce)

Theworkdonebytheconservatiiveforceonlydependsontheinitial&finalpositionsoftheobject&isindependentofthepaththatittook.1保守力作功特點(diǎn)(Thefeatureoftheworkdonebytheconservativeforce)

44/12質(zhì)點(diǎn)沿任意閉合路徑運(yùn)動(dòng)一周時(shí),保守力對(duì)它所作功為零.非保守力:力所作功與路徑相關(guān)(如摩擦力).WhenanobjectmovesaroundanarbitraryclosedlooptheworkdonebyconservativeforcesonitiszeroThenon-conservativeforce:Workdonebytheforcedependsonthepath(e.g

Thefrictionalforce)

2保守力作功數(shù)學(xué)表示式(Themathematicalexpressionofworkbytheconservativeforce)55/12三勢(shì)能(Potentialenergy)與相互作用物體相對(duì)位置相關(guān)能量.Energydependsonoftherelativepositionoftheinteractiveobjects引力勢(shì)能Gravitionalpotentialenergy引力功Workofgravitionalforce彈力功Workofelasticforce彈力勢(shì)能Elasticpotentialenergy66/12物體在地球表面附近距地面高為y時(shí),含有引力勢(shì)能稱為重力勢(shì)能保守力對(duì)物體作功等于物體勢(shì)能增量負(fù)值．保守力功(Workofconservativeforce)重力勢(shì)能(Gravitypotenial)Theworkdonebytheconservativeforceonobjectisequaltothenegativevalueoftheincrementofthepotenialenergyofthatobject77/12在一維情況下作用于物體上在Ox軸上保守力,等于勢(shì)能對(duì)坐標(biāo)x導(dǎo)數(shù)負(fù)值。TheconservativeforceactingontheobjectalongtheOxaxisisequaltothenegativederivativeofpotenialenergywithrespecttothecoordinatex88/12勢(shì)能是狀態(tài)函數(shù)討論Thepotenialenergyisafunctionofstate勢(shì)能含有相對(duì)性,勢(shì)能大小與勢(shì)能零點(diǎn)選取相關(guān),任意兩點(diǎn)間勢(shì)之能差卻是絕正確.Therelativityofthepotenialenergy,thevalueofthepotenialenergydependsontheselectionofthezeropoint,thedifferenceofthepotentialenergybetweenanytwopointhasanabsolutemeaning99/12勢(shì)能是屬于物體系統(tǒng).勢(shì)能計(jì)算(Calculationofpotenialenergy)Thepotenialenergybelongtothesystemofobjects討論1010/12

四勢(shì)能曲線(Thepotenialenerycurve)重力勢(shì)能曲線Curveofgravitypotenialenergy彈性勢(shì)能曲線Curveofelasticpotenialenergy引力勢(shì)能曲線Curveofgrav