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CHAPTER 6 – SOURCES OF ENERGY
6.1 Various forms and sources of energyListing various forms and sources of energy on EarthIdentify energy changesExplaining the main source of energy
Prepared by Allen
WHAT IS ENERGY
Energy is defined as the ability to do work
ELECTRICAL ENERGY Energy carried by an electric current Large amount: Generator and power
plant Other sources ?
LIGHT ENERGY Energy which enables us to see Main source: Sun Other sources ?
HEAT ENERGY Flows from a region with higher
temperature to a region with a lower temperature
Main source: Sun Other sources ?
POTENTIAL ENERGY Energy stored in a body due to its
condition or position
Energy stored in a body due to its condition
Energy stored in a body due to its position
KINETIC ENERGY Energy possessed by a moving object Effected by mass and speed
K.E=1/2 MV2
MECHANICAL ENERGY Total Kinetic and Potential Energy
possessed by an object Produced by: Machines, objects
changing their positions
Moving pendulum
CHEMICAL ENERGY Energy stored in a substance Energy released due to chemical
reactions Sources : Fuels, foods, batteries, green
plant
SOUND ENERGY The energy produced by vibrating
object
Sound energy is important because it enables us tocommunicate and have entertainment.Sound is also used to alert people of something
Sound energy can bedetected by our ears.
NUCLEAR ENERGY Released from fission or fusion
reactions which occur in atomic nuclei Eg: Hydrogen and Uranium Nuclear Fusion: ? Nuclear Fission: ?
FOSSIL FUELS Fossils - remains of microscopic
animal/plant that have decomposed Burning of fossils fuels produces heat
and light Coal, petroleum, and natural gas ? Usage ? Advantage of natural gas ? Disadvantages of coal?
RADIOACTIVE SUBSTANCES Uranium and Plutonium Usage of nuclear energy ?
Nuclear power plant
GEOTHERMAL ENERGY Process of transferring heat from
underground steam to heat up water and produce electricity
Electricity ?
Geyser
Volcano
GEOTHERMAL ELECTRICITY
BIOMASS FUELS Energy obtained from the burning of
organic material Make gaseous and liquid fuels
WATER Kinetic energy of water can be used to
generate hydroelectric energy Energy conversion involve? Disadvantages of hydroelectricity?
WINDo Moving air due to uneven heat around
the Eartho Eg: Windmills and wind turbineso Energy conversion involved?
WAVESo On surface of sea watero Consists of ?o How energy conversion occur?
TIDESo Due to gravitational pull of Moon and
Sun on sea watero Similar like hydroelectricity
THE SUN AS THE PRIMARY SOURCE OF ENERGY
Chemical energy in plants
Heat energy
Solar energy
Atoms - Nuclear - Geothermal
- Wind -Wave -hydroelectricity
- Food - Fossil fuels
CHAPTER 6 – SOURCES OF ENERGY
6.2 Renewable and Non-renewable Energy Define renewable and non-renewable sources of energyGroup the various sources of energy into
renewable and non-renewable energyExplain why we need to conserve energySuggest ways to use energy efficiently
Prepared by Allen
Renewable Energy o Energy that can be replaced when they have
been used.
MEANS : the supply of these energy sources will not be used up
Eg: ?
Non-renewable Energy o Energy that cannot be replaced and will finally
be used up.
o Eg: ?
SOLAR ENERGYo Energy that obtained directly from the Suno Renewableo Usage?o Solar cell and solar panel
THE NEED TO CONSERVE ENERGYo Benefits of energy in daily activities ?o Increase of world’s population and
machines leads to increase in energy consumed
o Most of energy used on Earth come from fossil fuels (Non-renewable Energy)
o Estimated times before depletions
Coal 300-1500 years
Natural gas 50-120 years
Petroleum 40- 70 years
EFFICIENT USE OF ENERGYo Conversion of energy usually not perfect; wasted
as heat energyo Eg:
Bulb (5% useful light energy, 95% heat energy) Car (25% useful and 75% waste)
o Due to fossil fuels are non-renewable, hence maximum energy efficiency was needed
o Way to achieve: Fuel efficiency: Modified engine Cogeneration plants Super-insulated buildings Reduce, Reuse, and Recycle
IMPORTANCE OF CONSERVING ENERGY Use and management of energy sources
1. Transport2. Development3. Agriculture4. Industry