Energy

Any thing, which is able to do work as defined above, possesses energy. We, therefore, define energy as the capacity to do work. Energy is measured by the amount of work that a body can do. Therefore, SI unit of energy is also joule.

Different forms of energy

We come across in our day-to-day life different forms of energy, like the mechanical energy, heat energy, electrical energy, chemical energy etc. Here in this chapter, we are mainly concerned with mechanical energy. The two types of mechanical energy are kinetic energy and potential energy.