Subjects/Basic Physics/Work, energy and powerSection 6Work, energy and powerWork of a constant forceCopy LaTeXW=F⋅d=FdcosθParallel caseW=FdView detail →Work of a variable forceCopy LaTeXW=∫r1r2F⋅drIn one dimensionW=∫x1x2Fx(x)dxView detail →Kinetic energyCopy LaTeXK=21mv2View detail →Gravitational potential energy near the surfaceCopy LaTeXUg=mgyChangeΔUg=mg(yf−yi)g approximately constant.View detail →Elastic potential energyCopy LaTeXUs=21kx2View detail →Work of a conservative forceCopy LaTeXWc=−ΔU=Ui−UfView detail →Work-energy theoremCopy LaTeXWneto=ΔK=Kf−KiView detail →Force from potential energyCopy LaTeXFx=−dxdUIn three dimensionsF=−∇UView detail →Mechanical energyCopy LaTeXEmec=K+UView detail →Conservation of mechanical energyCopy LaTeXKi+Ui=Kf+Ufonly conservative forces do work.View detail →Energy with non-conservative forcesCopy LaTeXKi+Ui+Wnc=Kf+UfEquivalentlyΔEmec=WncView detail →Work of kinetic frictionCopy LaTeXWf=−fkdFor motion on a flat surface with constant frictionWf=−μkNdView detail →Average powerCopy LaTeXPmed=ΔtWView detail →Instantaneous powerCopy LaTeXP=dtdW=F⋅vView detail →EfficiencyCopy LaTeXη=EentradaEuˊtilorη=PentradaPuˊtilView detail →
Gravitational potential energy near the surfaceCopy LaTeXUg=mgyChangeΔUg=mg(yf−yi)g approximately constant.View detail →
Conservation of mechanical energyCopy LaTeXKi+Ui=Kf+Ufonly conservative forces do work.View detail →
Energy with non-conservative forcesCopy LaTeXKi+Ui+Wnc=Kf+UfEquivalentlyΔEmec=WncView detail →
Work of kinetic frictionCopy LaTeXWf=−fkdFor motion on a flat surface with constant frictionWf=−μkNdView detail →