CHAPTER 6SOURCE OF ENERGY

What is energy?Energy is defined as the ability to do work.The unit of energy is joule (J).

ENERGYPOTENTIAL

KINETIC HEATCHEMICALELECTRICALNUCLEARLIGHTSOUND

Kinetic EnergyKinetic energy is the energy of an object due to its motion.All moving objects possess kinetic energy.The faster an object moves, the greater is its kinetic energy.All not moving objects have zero kinetic energy.

Gravitational potential energy because of their raised position.The gravitational potentialenergy of an objects dependson:The mass of the objectThe height or position of the object above the groundThe strength of the gravitational pull on the object

Potential EnergyGravitational Potential EnergyElastic Potential EnergyAll elastic substances when stretched or compressed possess elastic potential energy because of their stretched or compressed.

Energy stored in an object as a result of its position or its condition.

Gravitational potential energy

Elastic Potential Energy

Chemical EnergyChemical energy is the energy stored in substances such as food and fuels.The stored chemical energy is released and converted to other forms of energy when the substances undergo chemical reaction.

Sound EnergySound energy is produced by vibrating objects.Sound energy can be transferred from one place to another place in the form of waves through a medium such as air, water or solid.

Heat EnergyHeat energy is the energy found in the hot objects.The hotter the object, the more energy it can give out.Heat energy can increase the temperature of an object.

Light EnergyLight energy is the energy radiated by objects that give out light.

Electrical EnergyConsists of electric charges, which travel through electrical conductors or wires.Supplied in the form of electrical power by generators, batteries, dry cells and solar cells.

Nuclear EnergyNuclear energy is the energy stored in the nucleus of an atom.All radioactive materials store nuclear energy.

An atom of Uranium2 smaller atomsA lot of energyNuclear fission

The sun as the primary sources of energy

Sources of energyWindWaterNuclearSunBiomassWaveGeothermal

2 atoms of hydrogen1 atoms of helium

Energy ChangesPotential energy Kinetic energyElectrical energySound energyElectrical energy Kinetic energy + sound energy

Electrical Light energyenergy + heat energyElectrical Light + Sound+ Heat Energyenergyenergy energyElectricalKinetic energy + EnergySound energy

ChemicalHeat energy +EnergyLight energyPotential energy Kinetic energyKinetic energy Sound energy

Chemical Electrical Heat + LightEnergy energy energy energyElectrical energy Heat energy