变质量物体动力学方程的意义

©1994-2010ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.(,638300):,,,1:;;;:O347:A:1671-1785(2007)04-0044-031tm,v(vnc),$mu,$tm,t+$tv+$v1,$mmfm,m$mfdm,m(fm)Fm,$m(fdm)Fdm,m$mF1Fm+Fdm=F,fm+fdm=01111m$m,(m+$m)(v+$v)-mv-$mu=F$t,(1)m(v+$v-v)+$m(v+$v-u)=F$t,(2)$t,$t0,$m$vmdvdt+(v-u)dmdt=F,(3)(3)mdvdt=F-(v-u)dmdt(4)ddt(mv)-udmdt=F1(5)112$t,1,mm(v+$v)-mv=(Fm+fm)$t,$m(v+$v)$m-u$m=(Fdm+fdm)$t,$t,$t0,$m$v1mdvdt=Fm+fm,(6)(v-u)dmdt=Fdm+fdm1(7)fm+fdm=0,(6)(7),(3)1(3)(4)(5)(6)(7)122.1(3)(4)(5),1(6)(7)1(3)(4)(5),,,F1(6)(7),fmfdm,,,1[1,2,3],:[1](3)(4)(5),1,11[1]:(4)mdvdt()1:(4),,,,1(4)(6),F-(v-u)dmdt=Fm+fm,,Fdm-(v-u)dmdt=fm44JOURNALOFNEIJIANGTEACHERSCOLLEGE224No14Vol122:2007-03-26:(1965-),,,,1©1994-2010ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.(4)Fdm-(v-u)dmdt,,11[2]([1]),(u-v)dmdt,,Fdm1(7),Fdm-(v-u)dmdt.[1],dmdt(v-u)=f(e)-fm,dmdt(v-u)=f(e)+fm1[1,3],ddt(mv),1,ddt(mv)=(m+dm)(v+dv)-mvdt,,ddt(mv)m;,ddt(mv),m1,,,vnc,1,dpdt=ddt(mv),dpdt=mdvdt,ddt(mv)=mdvdt,,;,,ddt(mv),-udmdt,(v-u)dmdt,-udmdt(v-u)dmdt1,,ddt(mv),12.2,,1?$t,,,,1,tm,t+$tm+$m,,,,$t1$tm,mm,1.2.3(dmdt0),(dmdt0)11,()$m1$m2$mn1tv,t+$tv+$v1t(t+$t)u1u2un,F1mdvdt+(v-u1)dm1dt+(v-u2)dm2dt++(v-un)dmndt=F.(8)(8)12.4u=0,d(mv)dt=F1:1v=u,mdvdt=F1,,1,,F1dmdt=0,mdvdt=F,1F=0,mdvdt+(v-u)dmdt=0,13G,,m,11x0,v01x1,,1,1x,mx=Gx,dmdt=Gdxdt,v=dxdt1u=01T1()m,21m,5420078:©1994-2010ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.=ma,(9)d(mxv)dt=T-Gxg,vGdxdt+Gxdvdt=T-Gxg,(10)A=dvdt,v=dxdt1(11)(8)(10)(11)(m+Gx)dv2dx=-2Gv2+2(m-Gx)g,dv2dx=-2Gm+Gxv2+2(m-Gx)gm+Gx1(12)(12),v2=e-2Gdxm+Gx2(m-Gx)gm+Gxe2ndxm+Gxdx+c,v2=1(m+Gx)2(2gm2x-23gG2x3+c)1(13)x=x0,v=v0c=v20(m+Gx0)2-23gx0(3m2-G2x20),(13)v=1m+Gx2gm2(x-x0)-23gG2(x3-x30)+v20(m+Gx0)21(14),,G=0,m1G=0(14)v2-v20=2g(x-x0),,1,,:,1,,1,,1(),1,,11,,11:[1],,,1[J]1,2003,13(4):162181[2]1(2)[M]1:,1985113721391[3],11(5)[M]1:,20011741TheMeaningsofKineticEquationofChange-QualitySubstanceHUANGGuang2bing(DepartmentofElementary,Guang’anCollegeofVocationalTechnology,Guang’an,Sichuan638300,China)Abstract:Thisessay,first,derivesthekineticequationofchange2qualitysubstancebymeansofthetheoremofmomentumaboutmasspointandthesystemofmasspoint1Then,understandtheimplicationsoftheequationofphysicsfromtheviewpointofthemasspointanditssystem1Next,discusstheperspectivesinrelated2articles1Finallyenhancetheunderstandingandapplicationoftheequationbyconcreteexamples1Keywords:changequality;thesystemofmasspoint;theoremofmomentum;kineticequation(:)64224