Chapter 9 9.4

• Energy conversion during a roller coaster ride shows that energy is not created or destroyed, but transferred from one object to another or converted from one form to another.
• When a car moves from the highest point to the lowest point on a roller coaster, all gravitational potential energy is converted to kinetic energy of the car when it reaches the bottom of the track.
• Most of the energy found on earth comes from the sun, which gives out heat and light energy, supporting life on earth.
• Fossil fuels are formed from the remains of dead plants and animals buried in the earth millions of years ago, and are limited and will run out someday.
• In a power station, fossil fuels are burnt and undergo a chemical process which releases heat, converted to kinetic energy, and used to produce electrical energy.
• Nuclear energy research efforts include finding solutions to minimise potential risks to health and safety of communities living near the power plants.
• Nuclear energy has an impact on the environment as it requires less land and space to generate the same amount of energy as other methods.
• Nuclear energy undergoes an energy conversion from heat, kinetic energy, to electrical energy.
• Steam produced in nuclear power plants powers turbines to generate electrical energy.
• Designs are being developed to dispose and store nuclear waste without leakage.
• Research efforts are underway to develop newer and safer ways to generate energy through nuclear reactions.
• Nuclear energy is harnessed from the nucleus of an atom and can be obtained through nuclear reactions.
• A large amount of heat energy is released to boil water in nuclear power plants.
• Nuclear energy converts into electrical energy and nuclear power plants generate electrical energy using heavy atoms.
• Electrical energy is produced through the following energy conversions: chemical potential -> heat -> kinetic -> electrical energy (fossil fuels).
• Burning fossil fuels release air pollutants and greenhouse gases into the environment, contributing to global warming and increasing the rate of climate change.
• Trace of toxic elements buried underground are also drawn out, causing harm to the environment if not handled correctly.
• A generator connected to the turbine spins, generating electrical energy through the following energy conversions: Kinetic energy -> kinetic energy -> electrical energy (wind).
• A geothermal power plant uses heat from deep inside Earth to generate steam, powering a turbine in the following energy conversions: heat energy, kinetic energy -> kinetic energy/electrical energy.
• Biofuels carry out photosynthesis, helping to balance the amount of carbon dioxide released when biofuels are burnt.
• Geothermal energy is heat stored in Earth, harnessed to generate electrical energy.
• The noise produced by the rotating blade of a wind turbine is a source of noise pollution.
• The use of biofuels can release air pollutants such as carbon dioxide into the environment, but plants can be regrown back in a short amount of time.
• The use of Geothermal energy usually requires clearing of large areas of land, destroying habitats of wildlife and affecting diversity of species.
• Biofuels are made from animal waste or from plant materials that cannot be eaten by humans, and can be produced from the recycling of food waste such as using cooking oil or plant pulp.
• Ethanol is made from plants such as sugarcane and corn, used to power motor vehicles.
• The use of wind energy can lead to the potential loss of wildlife as natural habitats are destroyed.
• Alternative sources of energy such as solar energy, hydroelectric energy, wind energy, geothermal energy, biofuels, and nuclear energy are being used to reduce the use of fossil fuels.
• Birds may be killed if they collide into the rotating blades of the wind turbines.
• Hydroelectric energy is generated by turbines and is powered by moving water.
• A hydroelectric power station stores water in a reservoir behind a dam.
• Solar energy can be used in solar powered devices.
• The impact of the use of hydroelectric energy on the environment is that it produces very little greenhouse gases and the environmental impact of harnessing hydroelectric power needs to be considered minimal.
• Sufficient care needs to be taken to reduce the amount of toxic waste generated during the production and disposal of solar panels.
• The process of harnessing solar energy has minimal impact on the environment.
• The reservoir water floods the area behind a dams, killing plants and forcing animals to move to other areas.
• When water is released from the dam, the moving water powers the turbines to generate electrical energy in the following energy conversions: Gravitional potential energy -> Kinetic energy -> Kinetic energy -> electrical energy.
• People who make a living by fishing may also have to relocate further inland as they can no longer fish.
• When wind blows at it, the kinetic energy of the wind is transferred to the blades of the turbine to cause blades to rotate.
• Wind energy converts energy from wind to electrical energy.