This there is no distance in the direction of the motion and the force does no work . The work done on an object also depends on whether a mechanical device is used to move it. For example, if you want to lift a 500 pound box but you are capable of exerting only 100 pounds, you will not find it possible to lift the box directly. The figures below illustrate these points. Now we are ready for a definition of energy.
Energy is defined as the ability or capacity to perform work.
It should be clear that there must be some relationship between work and energy. First it would be useful to mention various forms of energy. Kinetic energy is energy associated with motion. Two examples of bodies possessing kinetic energy are a thrown ball and a moving car. Note that since the kinetic energy depends on both the mass and the velocity, it is possible for a very massive object moving at a small velocity to have the same, or more kinetic energy as a less massive object moving at a high velocity.