Does this work energy theorem is only the theoretical thing?
No, friends it is not like that.
We have till now studied, that this theorem states that the work done on any body is given by the change in its kinetic energy.
And this theorem is proved by using Newton’s second law.
It can also be easily proved by our simple kinematics. As, we already know by third law of motion which relates inbetween final velocity, initial velocity, acceleration and displacement.
Multiplying by mass M and dividing by 2, we easily gets the Work Energy Theorem.
And, as we know the work done in a moving body stored in it as its kinetic energy. And in simple words this is work energy theorem nothing else. So, imagine a vehicle starting from rest, you will get the net change in kinetic energy equal to the work done.
Hence, the concept of work energy theorem is easily be understood by our above discussion.