Physics111Exam1ReviewVariablestableVariable Name Unitsx Position Meters(m)x0 Initialposition Meters(m)v velocity Meters/second(m/s)v0 Initialvelocity Meters/second(m/s)a Acceleration Meters/second2(m/s2)t Time Secondst0 Initialtime SecondsΔt Changeintime SecondsF Force Newtons(Norkgm/s2)R Anyvector(F,a,v,etc) VariesRx ComponentofRinx-dir VariesRy ComponentofRiny-dir Variesθ Theta(anglewithx-axis) Degreesfk Forceoffrictiononamovingobject Newtons(Norkgm/s2)fs Forceoffrictiononastaticobject Newtons(Norkgm/s2)µk Kineticcoefficientoffriction Noneµs Staticcoefficientoffriction None1.HowtoapproachprojectileproblemsIftheproblemaskstofindtime…(vwillbegiven,awillequalg)1.Onlyanalyzethey-direction!2.Findcomponentsofallvectors(F,a,v,etc)inthey-direction3.UsetheappropriateequationonyourformulasheetIftheproblemasksyoutofinddistancetraveled(x-direction)…1.Usethestepsabovetofindtime2.Timeistheonlydimensionwherethesamevaluesaffectboththexandydirections,thereforefindthecomponentsofeverythinginthex-directionandplugintotheappropriateequation(usuallyconstantvelocity)2.Howtoapproachrelativemotion1.Findthemotionoftheobjectinquestionrelativetosomethingnotmoving2.Changecomponentsintothexandydirections3.Findallvaluesforeachdirectionandsolveformulasindependently

3.HowtoapproachproblemswithNewton’ssecondlawofmotion(Fnet=ma)Keepinmind:Fnetandaaretheonlytwovectors,soFnetandawillALWAYSpointinthesamedirection!1.Findthecomponentoftheforceinthedirectionofacceleration.Ifthisisappliedatanangle,usetrigtofindthecomponent.Andiftherearemorethanoneforceactingontheobject,makesuretousethesumoftheforces.2.PlugthisforceintoF=ma4.Howtoapproachequilibriumofforceproblems1.Setalltheforcesinthex-directionequalto02.Setallforcesinthey-directionequalto03.Solvethesystemofequations5.Howtoapproachfrictionproblems1.FindthenormalforceN.Thisisjustmgonlevelgroundwithnoforcepushingdownorupontheobject.2.PlugintotheequationtofindfNote:Ifaskedtosolveforacceleration,theforceinF=maisthenetforce,sofrictionwouldhavetobetakenintoaccount.