energy
Forms of energy: light energy, heat energy, sound energy, electrical energy, kinetic energy, potential energy, chemical energy.
Energy can change from on form to another.
In an energy conversion, intermediate forms of energy may be involved between the initial and the final forms of energy.
motors change electrical energy to kinetic energy.
generators change kinetic energy to electrical energy.
Energy converters can change energy from one form to another.
Motors and generators are common energy converters.
Controlled energy conversions provide useful forms of energy in a safe way.
uncontrolled energy conversions can be very dangerous.
common fuels: town gas, liquefied petroleum gas, petrol and diesel, kerosene, coal.
easy to light, clean when burnt, safe to use, give out a lot of heat energy when burnt, easy to store and transport.
we must take safety precautions when using fuels.
if there is a gas leak or if a fuel catches fire, we must stay calm and act quickly, we can read the guidelines published by the government to learn about what to do in case of a gas leak or a fire.
we must take safety precautions when transporting and storing fuels.
electricity is the most common energy source used at home today.
the principle of generating electricity is to change chemical energy to kinetic energy through a generator.
in some power stations, fuel are burnt to give out heat energy from boiling water to steam, the steam produced turns the turbine. the turning turbine drives the generator to generate electricity.
Fossil fuels are non-renewable source of energy, their supply is limited, they will be used up one day.
the air pollutants given out from the burning of fossil fuels can harm our health and cause acid rain.
some of the gases given out from the burning of fossil fuels trap more heat energy in the atmosphere and cause global warming.
we can reduce the use of fossil fuels and reduce air pollution by saving energy and using other energy sources.
solar power, hydroelectric power, wind power, nuclear power, tidal power, geothermal power and biofuels can be used to replace fossil fuels for generating electricity.
