Example : A body of mass 0.5 kg travels in a straight line with velocity v = a x 3 / 2 where a = 5 m – 1 / 2 s – 1 . What is the work done by the net force during its displacement from x = 0 to x = 2 m
Solution : We know that WD = Kf - Ki , now we can put value of x = 0 in the equation v = a x 3 / 2 to find initial velocity , vi = 0 , Ki = 0 , Similarly find vf by putting x = 2 , and Kf = ½ mv 2 .
Potential energy
o
Potential energy is the ‘ stored energy ’ by virtue of the position or configuration of a body . o
Physically , the notion of potential energy is applicable only to the class of forces where work done against the force gets ‘ stored up ’ as energy .
o Mathematically , the potential energy V ( x ) is defined , if the force F ( x )
can be written as o
This relation is valid only for Conservative Forces