Chapter 39 - Energy Flashcards
What is energy measured in?
The ‘joule’
Symbol: J
What is energy?
The ability to do work or move something.
What makes energy different from matter?
It has no mass and takes up no space.
What does the principle of conservation of energy state?
Energy cannot be created or destroyed, only change from one state to another.
What are different types of stored energy?
Potential energy - due to height or shape
Chemical energy - fuel, food or a battery
Nuclear energy
What are different does of energy in action?
Kinetic energy - moving objects Light energy Heat energy Sound energy Magnetic energy Electrical energy
What is the original source of most of our energy supplies?
The sun
Where is the suns energy used, apart from energy supplies?
The plants use it to make food - photosynthesis
What is the difference between renewable and non-renewable sources?
Renewable sources have infinite supplies, unlike non-renewable sources, like fossil fuels - coal, oil, peat, gas.
What are the disadvantages of using fossil fuels?
They pollute the air, soil and water, and contribute to the greenhouse effect.
What are some renewable sources of energy?
Wind energy Tidal energy Solar energy Biomass energy Wave energy Hydroelectric energy Nuclear energy Geothermal energy
What is biomass?
The chemical energy stored in fast-growing plants such as trees and oil-seed rape. Methane can be produces as a biogas.
Where does geothermal energy come from?
Beneath the surface of the earth, due to radioactive material heating the rocks far below the surface.
What happens to most of the energy in the world?
It ends up as wasted heat.
When does an energy conversion take place?
When energy changes from one form to another, usually to produce a more useful form of energy.
