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Key Equations

# Key Equations

 impulse $FnetΔtFnetΔt$ impulse–momentum theorem $Δp=FnetΔtΔp=FnetΔt$ linear momentum $p=mvp=mv$ Newton’s second law in terms of momentum $Fnet=ΔpΔtFnet=ΔpΔt$
 law of conservation of momentum ptot = constant, or ptot = p′tot conservation of momentum for two objects p1 + p2 = constant, or p1 + p2 = p′1 + p′2 angular momentum L = I $ωω$
 conservation of momentum in an elastic collision $m1v1+m2v2=m1v′1+m2v′2,m1v1+m2v2=m1v′1+m2v′2,$ conservation of momentum in an inelastic collision conservation of momentum along x-axis for 2D collisions $m1v1=m1v′1cosθ1+m2v′2cosθ2m1v1=m1v′1cosθ1+m2v′2cosθ2$ conservation of momentum along y-axis for 2D collisions $0=m1v′1sin θ1+m2v′2sin θ20=m1v′1sin θ1+m2v′2sin θ2$