We all have heard the stories of great explorers who sailed the unknown seas in their sailboats.  Those were the days before any engine was in existence.  They only relied on wind to move their huge ships. How does the wind move such objects? The answer lies in the principles of Kinetic energy.  In this article, we shall understand its basic principles and how can it equate to work.Kinetic Energy of an object is its capacity to put another object in motion. A force displacing an object does work. Also, we know that when an object in motion strikes a stationary object, it can cause it to move. Hence it can do work. Thus, we define the kinetic energy as the capacity of an object to do work by virtue of its motion.The kinetic energy of an object is denoted by KE and its SI unit is joules (J). By now, we have started to sense that work and kinetic energy are closely related.  But, are they interchangeable? Can work be expressed in terms of the kinetic energy of an object and vice versa? Let us see!