GCSE›Edexcel GCSE Physics›Mind mapsForcesEdexcel GCSE Physics: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsFirst lawZero resultant force: rest or constant velocityNon-zero resultant force: speed or direction changesConstant velocity needs no forceSecond lawF=maF = maF=maBigger force gives more accelerationBigger mass gives less accelerationWeight: W=mgW = mgW=mgg is gravitational field strength (N/kg)Same mass, less weight on the MoonInertial massHow hard it is to change velocitymass=Fa\text{mass} = \frac{F}{a}mass=aFForcesNewton's lawsNkgm/s²Circular motionConstant speed but changing velocityChanging velocity means accelerationResultant force is centripetalActs towards the centreThird lawForces are equal and oppositeAct on different objectsSame type of forceUnderpins conservation of momentumExam tipsConvert grams to kg in F=maF = maF=maWeight and contact force are not a third-law pairNewtonmeter measures weight