WORK AND POWER!

Vector Dot Product!




W = ∫ F·dr

This is the basic definition of work!!!!

For a constant force, the force F can be taken out of the integral, to get the result

W = F·Δr

Note that since v = Δr/Δt we can also write W = F·vΔ t.



Note that neither of the two forces acting are doing any work!




The delivered power is the rate at which work is done. For example the power P delivered by a force F to a body traveling at velocity v is F·v.


The kinetic energy can be used to keep track of the work done by forces on a body: WF = ΔK


Notice that if we introduce the magnitude of the momentum, p = mv, we can also write the kinetic energy as K = p2/(2m)

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