Workdone vs Energy
When you hit a golf ball with a golf club, you exert force on the club which in turn exerts force on the ball. So the energy of the golfer is transferred into energy in the club and finally into energy in the ball. We all know that the energy can neither be created nor destroyed and the total energy of the universe remains constant. In the above example, the golfer does work on the club, which turns into work done on the ball. The final result is the movement of the ball. Thus, the work is the transfer of energy. Let us take a closer look at the concept.
Whenever work is done upon an object, a force is applied on to it and the object is displaced because of this force. The amount of work is calculated by multiplying the force applied with the displacement of the object. Work energy principle states that the change in the kinetic energy of an object is equal to the net work done on the object. This is the most important principle that helps in solving mechanics problems. It is derived from the law of conservation of energy and uses the relationship between work and energy.
To explain it to a layman, work refers to application of force on an object that changes the position of the object causing a displacement. The product of the force applied and the displacement of the object is the work done on the object. Energy on the other hand is described as the capacity to do work. You need energy to do any kind of work. If someone says that he does not have the energy required to do the job, he is merely reiterating this work energy relationship. Energy is like currency in hand which you use for shopping. Greater the energy you have, more is the amount of work you can perform.
Difference Between Work done and Energy
• Work is transfer of energy
• Work is done on an object when you transfer energy to that object
• The change in the kinetic energy of an object is the net work done on it
• The rate of doing work is same as that of consuming energy