Power

  • Time rate at which work is done

The average power

Pav=ΔwΔt
  • Δw is the average quantity of work done

  • Δt is the time interval

Units of Power

Wat=Joulesecond

Instantaneous power

P=limΔt0ΔwΔt

If forces act on a moving object, we can express the corresponding power in terms of force and velocity:

Pav=FΔsΔt=Fvav
  • Δs is the magnitude of displacement Δs

Int the limit we get the instantaneous work:

P=Fv