Energy

     You can do your activity if you have energy. Beside that, horse can attract cart because the horse has energy. Energy is defined as ability to perform work. Energy unit in International Standard is Joule (J). The other unit for energy is calorie, 1 joule = 0.24 calorie.

      Energy has several forms. The forms of energy can alter. How this happen? concern the following explanation.

1. Energy Form
    Viewed from the source, energy has various forms. The forms of energy are potential energy, kinetic energy chemical energy, heat energy, electrical energy, sound energy, nuclear energy and radiation energy. Explanation of the energy forms as follow.

a.  Potential energy
     Potential energy is energy contained in motionless object. This energy also called idle energy. For