Notions of Work and Kinetic Energy o
o
The work-energy theorem states that the change in kinetic energy of a particle is equal to the work done on it by the net force .
Kf - Ki = W
o We know the equation in 3D : v 2 – u 2 = 2a . d ( where u-initial velocity , v-final velocity , a-acceleration , d-displacement ) now multiplying the equation by m / 2 we have , ½ mv 2 – ½ mu 2 = ma . d = F . d ( Since ma = F )
Work The work done by the force is defined to be the product of component of the force in the direction of the displacement and the magnitude of this displacement . W = F . d . No work is done if : o
The displacement is zero