6.1 The Various Form and Sources of Energy
- Energy is defined as the ability to do work. Energy is measured in joules (j).
- Energy can be found in many forms :
a) Kinetic Energy
- Kinetic energy is the energy possessed by a moving object.
- The kinetuc energy of an object depends on ots mass and velocity.
|example of kinetic energy-running of leopard|
b) Potential Energy
- Potential energy is the energy stored in a body due to its position (gravitational potential energy) or its physical condition (elastic potential energy).
- The gravitational potential energy of an object depends on : the mass of the object, the distance of the object from the Earth's surface, and the power of the gravitational pull on the object.
- A falling object gain kinetic energy but loses potential energy.
- Elastic potential energy exists in only elastic substances such as spring or a rubber.
|elastic potential energy|
c) Heat Energy
- Heat energy is the energy that is stored in hot object.
- The heat energy of a body depends on its temperature and volume.
d) Light Energy
- Light energy is the energy produced by an object that emits light.
- Light energy can travel in a vacuum and in a straight line in the form of waves.
|example of light energy|
e) Sound Energy
- Sound energy is the energy produced by a vibrating object.
- The vibrating air forms sound waves.
|example of sound energy-drum|
f) Chemical energy
- Chemical energy is the energy stored in a chemical substance.
- When substance undergoes chemical reaction, chemical energy which is stored will be released and converted into other form of energy.
|example of electrical energy-battery|
g) Electrical Energy
- Electrical energy is the energy produced by the flow of electric charges
|example of electrical energy|
h) Nuclear Energy
- Nuclear energy is the energy stored in the nucleus of an atom.
- Also known as atomic energy.
|example of neclear energy-nuclear plant|
i) Mechanical Energy
- Mechanical energy is produced when a machine or object change its position.
|example of mechanical energy-used in meter glass|
j) Solar Energy
- Solar energy is produced during the process of nuclear fusion in the Sun's core.
- Almost all the energy currently available comes from the Sun.
|Solar energy comes from Sun|
Sources of Energy
Types of energy source on Earth
- Fossil fuels
- Biomass fuel
- Radioactive substance
- Mechanical sources
- Geothermal sources
6.2 Renewable and Non-Renewable Energy Source
- Renewable energy source of energy are energy sources which can be used again because the supplies are not limited. Example : wind, solar, hydro, wave, biomass, etc.
- Non-renewable energy sources of energy are sources of energy which are limited in supply and will be used up in a short period of time. Example : fossil fuels and radioactive souurces.