2020年-2021年初三物理总复习知识点大全

112341234123412345123451234123123123412312341232020-2021212312312345123412312341231234512341234531(m)(km)(dm)(cm)(mm)(m)(nm)2(s)(h)(min)3121v=S/ts(m)t(s)v/(m/s)m/sms-1km/hkmh-11m/s=3.6km/hv=S/ts=vtt=S/v12mins3v=S/t12431234m/sv=S/t340m/s;10.1s2S=V*TL=S/2123120Hz20000Hz20000Hz20Hz212B35112234dB90dB0dB51()23212010001001001355202020112363542123451AB2BC503CD4DE5EF506FG71231,12342123312344123128340506071;21234341c=3108m/s;2100m12351923612312312123110230,45112345123412D121CC2O3F114f512312121212uv5u2ffv2f4u=2fv=2f3fu2fv2f2u=f-------------------1ufVf121234513123451234611712Vm33313=1000340414mV11m1V1V2221m1Vm22ambm1cm21.(1)(2)152.(1)(2)(3)N(4)3.(1)(2)4.1.(1)(2)2.(1)(2)3.(1)(2)(3)161.2.(1)(2)G=mgG(N)m(kg)g=9.8N/kg(3)3.(1)(2)4.(1)(2)5.1.(1)(2)(3)(4)(5)172.(1)(2)(3)1.(1)()(2)(3)2.3.(1)18(2)4.1.2.(1)(2)(3)3.(1)(2)(3)4.(1)0fFmax(2)5.(1)(2)(3)(4)6.(1)(2)()191.(1)(2)(3)(4)p=F/SpFS(5)Pa1Pa=lN/m2lm21N2.(1)(2)1.2.(1)(2)(3)(4)3.(1)(2)p=ghp(Pa)(kg/m3h(m)3.(1)20(2)1.2.3.(1)1m76cm(2)p0=p=gh=13.6103kg/m39.8N/kg0.76m=1.013105PaP0=1.013Xl05Pa=760mmHg(3)(4)(5)3.3000m10m100Pa4.()5.1.2.1.2.3.=-F=G-F4.1.F=G21(1)F=G=mg=gV(2)2.F=GVV=VVVV=V+VF=gV-FVF=gVV=V1.(1)(2)FGFGFGFGFG2.(1)mm+m(2)22(3)()3.F=G-FF=F-FF=G=mg=gVF=G1(1)(2)(3)2(1)W=Fs(2)W(J)1J=1NmF(N)s(m)(3)FsFFFsNmJ12(1)PWkW1kW=103W(2)P=W/tPWt112J223(1)(2)3(1)(2)4(1)(2)1(1)(2)J2(1)(2)(3)3(1)19(2)4.(1)(2)(3)241.(1)(2)(O)(F1)(F2)(l1)(l2)2.(1)(2)=F1l1=F2l2(3)03.(1)(2)(3)1.(1)(2)2.(1)(2)3.(1)(2)(3)s=nhnhnGGF254.(1)F2F1rRF1R=F2rRrF1F2(2)1WW=Gh2W(1)(2)3W(1)W=W+W(2)FW=F?s4(1)(2)=W/W(3)1(4)(3)1262r0r0=10-10m0r0r010r01J232711cJ/(kg)c4.2103J/(kg)1kg14.2103J2Qcmtt0cQmtt0mQctt0tQcm+t0t0t-QcmQcmt0tcQmt0tmQct0tt0Qcm+ttt0-QcmQcmtcQmtmQcttQcmQJcJ/(kg)mkgtt0101010t10tQcmt281222129341kgqJ/kgJ/m3Qqmm=Qqq=QmQJqJ/kgmkgQqVV=Qqq=QVQJqJ/m3Vm33.0107J/kg1kg3.0107J3.9107J/m31m33.9107J30QQQ=QQ=Q16%15%20%30%30%45%1QC231ee6.2510181C31-2345133245M()()AV121IAmAA,1A=103mA1mA=103A1A=106A1stQIt=QIQ=ItIAQCts332A*00.6A-0.60.2A0.02A03A-31A0.1A03A00.6A5*+0.630.63+0.63+0.6A1UVkVmV1kV103V1V103mV1kV106mV2V34*03V-31V0.1V015V-155V0.5V015V03V5*+315315+315+3V220V36V1.5V2V31RMk1M103k1k1031M1062LS352R=LSnn2n1n21501A501AAB0CDABACBCADBDCPDP2341361I=URR=UIU=IRUVRIAR=UI2nIIII21nIIII21nUUUU21nUUUU21nRRRR21nR00nRRnRRRR111121R1R2R=R1R2R1+R2nR0nRR0U1U2=R1R2I1I2=R2R1*R=UI37R=UIPR=UIU/VI/AR/R/1231WJkWh1kWh3.6106JW=UItU=WItI=WUtt=WUIW=I2RtI2=WRtI=WRtR=WI2tt=WI2RW=U2RtU2=WRtU=WRtR=U2tWt=WRU2W=UQU=WQQ=WUW=PtP=Wtt=WPWJUVIAtsRQC38PW31234.5kWh220V220V220V1020A10A20A50Hz50Hz600revs/kWh1600h600revs/kWh1kW4W1W2=R1R2;W1W2=R2R111PWkW1kW103WP=WtW=Ptt=WPPWWJtsPkWWkWhthP=UIU=PII=PUP=I2RI2=PRI=PRR=PI2P=U2RU2=PRU=PRR=U2PPWUVIAR239P1P2=R1R2;P1P2=R2R13UUPPUUPPU=UP=PPZ22025220V25WPRPRnIIIIRIP212nUUUURUP212nIIIIIUP21PnUUUUIUP21PnIIIIRIP212PnUUUURUP212P40UIPP=UI1.2P=UIP=UIU/VI/AP/W123Q=I2RtI2=QRtI=QRtR=QI2tt=QI2RQ=UItU=QItI=QUtt=QUIQ=U2RtU2=QRtU=QRtR=U2tQt=QRU2Q=PtP=Qtt=QPQJIARts41PWUVQWQ=UitQ=U2RtQ=PtQQI2RtQ1Q2=R1R2;Q1Q2=R2R11220V220V0V2344256789PEN43RUIR1000V1000V1SN442NS3123N45123124612DCACHz220V50Hz0.02s1s50250Hz1s100118761223c,c=3108m/s=3105km/sf1m472fHzHzkHzMHz1MHz=103kHz1kHz=103Hz1MHz=106Hz3cm/s4c=f=cff=c5f30000m~3000m10kHz~100kHz3000m~200m100kHz~1500kHzAM200m~50m1500kHz~6000kHz50m~10m6MHz~30MHzVHF10m~1m30MHz~300MHzFMUHF10dm~1dm300MHz~3000MHz10cm~1cm3000MHz~30000MHz10mm~1mm30000MHz~300000MHz123448110m~1mm30MHz~[e-mail]49121350