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chapter 15: energy and work done - Coggle Diagram
chapter 15: energy and work done
energy: the ability to do work
2 conditions:
a force acts on the objects
the object moves in the same direction as the force
energy changes
energy can be converted from one form to another, but it cannot be created or destroyed
e.g an archer puling a bow string
chemical potential energy in arm muscles ----- elastic potential energy in the bow and bowstring.
another e.g an arrow getting shot out of a bow
elastic potential energy in the bow and bowstring----kinetic energy in the moving arrow
e.g on a swing
gravitational potential energy---kinetic energy---gravitational potential energy
Sources of energy
renewable sources of energy
e.g biofuels
uses on the environment:
ethanol derived from sugarcane and water hyacinth can be turned into biodiesel fuel for motor vehicles
impacts on the environment:
carbon dioxide is produced when biofuels are burnt, contributing to the heat trapped in the earths atmosphere. however, the plans that produce these biofuels take in carbon dioxide during photosynthesis. if these plants are grown as quickly as they are burnt, it will partially offset the contribution to trapping of heat in the atmosphere.
geothermal energy
heat---kinetic energy---electrical energy
uses:
steam from heated water in geothermal power stations can be used to heat homes and buildings or generate electricity
impacts:
can extract poisonous substances such as hydrogen sulfide or arsenic from deep underground
land around the area may sink due to the materials extracted from deep underground
hydroelectric energy
gravitational energy---kinetic energy---electrical energy
hydroelectric power stations supply electrical energy to households and factories
impacts:
do not produce pollutants
can cause extensive flooding in large areas of forest, wildlife habitats and farmland.
prevent flow of sendiments and nutrients down the rivers, ecosystems affected
solar energy
light energy---electrical energy
uses:
heat water, generate electrical energy
impacts:
there are no negative impacts, no pollutants produced
wind energy
kinetic energy---electrical energy
uses:
provide electricity for households and research stations in remote areas
impacts:
kill birds with the wind blades
cause people to feel nauseous and experience headaches because of the production of low-frequency noise, including infrasound, from the wind turbine.
experience headaches if exposed to infrasound for long periods of time.
non-renewable sources of energy
e.g. fossil fuels in power stations
chemical potential energy--heat---kinetic energy---electrical energy
e.g fossil fuels in motor vehicles such as cars and motorcycles
chemical potential energy---heat----kinetic energy
impacts of fossil fuel on the environment:
carbon dioxide produced will trap heat from the sun in the earth atmosphere. the heating up of the atmosphere is causing ice in the North and south poles to melt, raising sea levels. global warming also causes more unpredictable and destructive weather patterns