year 7 - energy Flashcards
Unit to measure energy
joule(J)
Source of energy for human body
food
Why do humans need energy?
1) to grow and repair 2) to move 3) to keep warm
What kind of energy is stored in food, petrol and cells?
Chemical energy
What are the four methods of energy transfer?
heating, radiation(light, sound), electricity and forces
Which form of energy is stored in moving objects?
Kinetic Energy
Energy can neither be created not be destroyed, It can only be transferred from one store to another. What is this law called as?
Law of Conservation of energy
What form of energy is stored in a hot object?
Thermal Energy
What is the energy stored in stretched string?
Strain Energy or Elastic Potential Energy
Energy stored on an object at a height?
Gravitational Potential Energy
One of the most widely used Nuclear fuel ?
Uranium
The energy (chemical or nuclear) stored in fuels can be released by ———-?
burning
Three examples for fossil fuels
Crude Oil, Natural Gas, Coal
Petrol and diesel are made from which fossil fuel?
Oil
Which fossil fuel is made from plants which dies millions of years ago?
Coal
Fossil fuels are renewable resource or non renewable?
Non renewable (they are not replaced at the rate they are being used and will finally run out)
A Gas, which is the main substance in Natural Gas, produced from animal and plant waste?
Methane
Bio fuels (made from plants and animal waste) are renewable/ non renewable?
Renewable
Solar Cells cannot work at night, why?
Solar cells convert nuclear energy from the sun which is transferred in the form of light and heat. Since at might solar energy isn’t available, cells wont be able to produce electricity.
What is the source of energy for solar panel?
Sun/solar energy
What is the useful transfer of energy when coal is burned?
Chemical Energy to ThermalEnergy
Some energy is wasted into the surrounding when coal is burned, name one type of energy which is released and not useful.
sound, light
Wind turbine generates Electricity. Wind turns the turbine blades and turbine blade turns the generator. Here___________ energy is transferred to _______ energy
Kinetic to Electrical
Sugar cane is a plant. Sugar from cane is used to make alcohol which is a fuel. What is the energy source for the plant to produce sugar?
Sun(light)
Why is wood a renewal energy resource?
wood can be grown more by planting more trees.
When wood is burned chemical energy from the wood is transferred into _______ energy to the surroundings.
Thermal energy
Name a renewable resource which is available all the time
hydroelectric or geothermal
Sun is a store of ______ energy some of which is transferred by light and heat,
Nuclear
An energy resource which doesn’t depend on sun
Nuclear fuel, tidal power and geothermal power
Two disadvantages of fossil fuels
produces polluting gases (CO2) when burned.
Non-renewable
