ENERGY AND ITS FORMS
Energy may be defined as the ability to cause change in matter or simply as the ability to do work.
Work is done when a force is expended to move an object from one point to another. When work is done energy is transferred from one body to another, thus energy may also be defined as the rate of doing work.
Energy may be that due to motion otherwise referred to as kinetic energy or as potential energy due to its position. Generally speaking energy exist in different forms, i.e. as mechanical, chemical, electrical,
nuclear, thermal, electromagnetic and sound energy. These forms of energy are described below;
- MECHANICAL ENERGY.
Mechanical energy is the energy of an object that is moving or has potential to move.it is the sum of an object kinetic and potential energy.
Many devices are employed to convert mechanical to or from other form of energy. For instance, an electric motor converts electrical energy to mechanical energy and an electric generator is used to convert mechanical energy to electrical energy.
- CHEMICAL ENERGY.
Chemical energy is stored in bonds between atoms that make the compound. If the bonds between these atoms are broken in a chemical reaction, energy is released. Thus chemical energy of a chemical substance can be transformed to other forms of energy by a chemical reaction. For example when a fuel is burned, the chemical energy of the molecular oxygen and the fuel is converted to heat energy.
- ELECTRICAL ENERGY.
Electrons are negatively charged particle orbiting an atomic nucleus; hence they can be easily stripped and caused to move from one point to another under an applied voltage difference between these points. This electron movement or flow releases electrical energy.
Electric heating is a clear example of converting electrical energy to heat energy.
- NUCLEAR ENERGY.
The nuclei of atoms are held together by powerful forces. This gives them a tremendous amount of stored energy, called nuclear energy. Thus this energy can be released to do work during nuclear fission or fusion. For example the use of sustained nuclear fission or fusion reaction is used to generate electricity.
- THERMAL ENERGY.
The atoms that make up matter are in constant motion and collision. These motion and collision generates thermal energy in the matter. Thermal energy thus generated is the total kinetic energy of all the atoms that make up an object. Thermal energy is physically exhibited as heat. Examples of thermal energy include heaters or any object or substance that is subjected to heat.
- ELECTROMAGNETIC ENERGY.
Energy released from the sun and stars into space are called electromagnetic energy. This form of energy can travel through space as electrical and magnetic waves. Electromagnetic energy is commonly called light. However, it includes infrared (visible light) as well as ultraviolet light, radio waves, X-rays, and gamma rays; all of which are part of the electromagnetic spectrum.
- SOUND ENERGY.
Sound energy is a form of energy that can be heard by living things. Only those waves that have a frequency of between 16HZ to 20KHZ are audible to humans. Sound energy can travel through air, water or any substance, but not through empty space (vacuum).