Law of conservation of Energy says that energy can neither be created nor get destroyed

Law of conservation of energy says that energy can never be created or it cannot be destroyed. Only energy can get transferred from one form to another form. There are various forms of energy such as potential energy and kinetic energy.

Different forms of Energy
Potential energy is the energy possessed by an object by virtue of its position. It indicates that if there is any object which is placed at any position in the universe, it has a potential energy associated with it. Now, if this object starts moving on its own and starts getting accelerated, then potential energy slowly gets changed into another form, i.e. kinetic energy.

Kinetic energy is the form of energy that is possessed by an object by virtue of its motion. The formula for Kinetic energy is

k = 1/2 m v^2

Here, k = kinetic energy
          m = mass of the object
          v = velocity of the object

So, if an object of 20 kg is moving with 30 m/s, then the kinetic energy possessed by that object is

k = 1/2 * 20 kg * 30^2

  = 9000 Joules