1、留學(xué)啦留學(xué)啦留學(xué)啦留學(xué)啦留學(xué)啦留學(xué)啦:htp:htpSAT2 物理考點/公式總結(jié)SAT II PHYSICSVector and For1. 1vertorque=force length of moment armthe sum of the clockwise moments=the sum of the counterclockwise momentsMotion and Foraverage speed= distance coveredtime requiredaverage velocity= displacementtimedistance covered=average spe

2、ed timeS=vavtacceleration=change in velocitytime required for change vvi ta v f tMotion with constant acceleration (starting from rest) v f / 2vavv f at (vf gt)留學(xué)啦留學(xué)啦留學(xué)啦留學(xué)啦S 1 at 2 (S 1 gt 2 )22v f 2as(v 2gs)22f average speedvavv f final velocitya accelerationt elapsed times distance covered vi v fv

3、av2v f vi atS v2iv 2 v 2 2asfiFt changeomentum=mass change in velocitymomentum=mass velocityCentripetal Forcev2 rmv2ac Fc rv 2 rT4 2 ra T 2Graviional FieldsF Gm1m2r 2GMsv rWork, Energy, Simple Machineswork forcedistancegraviional potential energy=wh=mgh12kinetic energy=mv2energy produced=mc2留學(xué)啦留學(xué)啦留學(xué)

4、啦留學(xué)啦coefficient of sliding friction= force of friction during motionnormal work against friction=friction distance object moves12elastic potential energy=kx2er worktimeer force distancetimeactual mechanical advantage(AMA)=actual effortAMA= FRFEwork output=work output=FR RRdistancemoveswork input=eff

5、ort distance effort moves work input=FE SEUnder ideal conditions there is no useless work. Thenwork output=work inputFS IMA(ideal mechanical advantage) R E FESRFor a machineefficirncy= work outputwork inputefficiency= AMA ideal effortIMAactual effortweight of object length of plane IMAideal efforthe

6、ight of planeFluid Mechanics留學(xué)啦留學(xué)啦留學(xué)啦留學(xué)啦massvolumedensity For solids and liquids:sp.gr. density of substancedensity of waterweight of substancesp.gr. weight of equal volume of watermass of substancesp.gr. mass of equal volume of waterP FAP hdg (h=height, d=density)F hdgA(diameter of largston)2FAIMA

7、fa(diameter of small piston)2For a solidt sinks in water:weight in airsp.gr. apparent loss of weight in waterFor a liquid:sp.gr. apparent loss in weight of solid in liquid apparent loss in weight of solid in waterHeat, Temperature, Thermal Expanchange in length=oringinal length coeff. of expantemp.

8、changeV1 T1VT221 V=volume, T=absolute temperature, P=prere21 2 T1T2Measurement of Heatheat required for melting=mass HFheat required for vaporization=mass HVheat gianed(or lost)=masssp.ht.temp.change+mass melted heat of fu+mass vaporized heat of vaporizationHeat and Work; Heat Transferheat flow=chan

9、ge in Q= U+Wernal energy+work done by systemWave Motion and Sou nd留學(xué)啦留學(xué)啦留學(xué)啦留學(xué)啦Periodic MotionFor a stretched spring:F kxmkT 2For waves:T1fv f ( =wavelength)the number of beats=the difference betClosed Pipes =4ln the two frequenceaVibrating Air Columns Open Pipes =2la =2lsGeometrical Optics: Reflecti

10、on and RefractionFor a spef R / 2l mirror the focal length is equal to one-half of the radius of the spherical sLaw of Refractionn sin 1 (n index of refraction)sin2n speed of light in vacuum(or air) speed of lighthe substancen2 sin1n1sin2Images Formed by Lenses111object distanceimage distancefocal l

11、ength1 1 1pqfsize of image image distance magnification(m) size of objectobject distanceOBJECT DISTANCEIMAGE CHARACTERISTICSConvex Lens(or Concave Mirror)greatern 2f 2fbetn f and 2flessn freal, smaller, betn f and 2f, inverted real, same size, 2f, invertedreal, larger, greatern 2f, inverted virtual.

12、 ;larger, q moren p, erect留學(xué)啦留學(xué)啦留學(xué)啦留學(xué)啦escopic magnification= focal length of the objectivefocal length of the eyeceensity of sourceillmination distance2Physical Optics: x dL wavelengtherfere nce and Diffractiond=distance bet L=distance betx=distance betn the two siltsn the barrier and the screenn th

13、e centralum and thebright fringeSic ElectricityElectric CircuitsF k2d 2E F / q (E=electric fieldensity,F=the force exerted onitive charge q)workchargepotential difference= workVqE V / d (E=electric fieldensity,V=the difference of potential betn the plates) workVqL lengtheterskL R=in ohmsR A A=cross-

14、sectional areaeter2k=a constant for the material and is called resistivity; unit is ohm-meterIT VT / RT RT VT / IT VT IT RTseries circuitparallel circuitseries-parallel circuitcurrentIT I1 I2IT I1 I2IT I3 I1 I2RT R 1 R21 1 1RTR1R2R R R1 R2T3R R12Concave Lens(or Convex Mirror)any distancevirtual smal

15、ler, erect, q lessn p留學(xué)啦留學(xué)啦留學(xué)啦留學(xué)啦VT emf Ir H 0.24I 2 RtH I 2RtI ; P I 2R;2 / Renergy er timeMagne tism; Meters, Motors, GeneratorsF ILB (L the length of wireF qvB (v=velocity)he magnetic field, B=the flux desity)second emf number of turns on secondaryprimary emfnumber of turns on primaryd by seconda

16、ry=efficiency ererd to primarywhen the efficiency is 100%, efficiency 2 / T 2 f I Imax sin tV Vmax sin tV Imax R sin tP I 2R I 2R sin 2 tmax 1 I 2I 2max21 I 2I 0.0707Irmsmaxmax2P I 2R 1 I 2Ravgrmsmax2 0.707VmaxVrmsElements of Electron ics Capacitors and Capacitance Q=CV1 farad 106 microfaradsvoltageVT V1 V2VT V1 V2VT V1 V3 V2 V3 ;V1 V2IR-dropVT IT RT ;V1 I1 R1 ;V2 I2 R2 , etcsymbolsI1 current through R1 ;V2 potential difference across R, etc.留學(xué)啦留學(xué)啦留學(xué)啦留學(xué)啦potential energy= 1 CV 22Q2C11P.E. CV QV 222Photons, Atoms, NucleiEk hf WEk kinetic energyh=