Energy Flashcards
State the law of conservarion of energy?
Energy camnot be created or destroyed, only transferred
Why do you need energy?
Breathe, move, grow
What are the 8 energy stores?
Chemical - objects
Thermal - heat
Kinetic- movement
Gravitational potential
Elastic - stretch, squash
Magnetic
Electrostatic
Nuclear
Desribe energy stores when cooking soup?
Cold soup - large chemical, small thermal
Hot soup - small chemical, large thermal
Describe energy storage in a torch?
Object is chemical
Converts to
Battery is electrical
Bulb is thermal
State unit of temperature vs unit of energy
Celsius / joules
State 4 pathways that transfer energy?
Conduction, convection, radiation and mechanical
How is energy transferred using conduction?
Molecules vibrate ( molecules themselves dont get warm) as they are delocalised/free to move about. These moving particles cause transfer of energy to the touching object
How is energy transferred during convection, eg radiator or soup in saucepan?
The source with the energy store (liquid or gas)heats up closest to the heat source moving from one location to another. Heat rises so the colder fluid/gas moves to the bottom replacing the hot liquid or gas in a current.
Why is metal a good conductor of heat?
Packed delocalised electrons.
What is a thermal insulator?
A substance that retains heat and is not a good conductor eg plastic, liquid, gas
How does a woollen jumper keep you warm in winter?
The jumper is made frim wool which is a good insulator as well as tge air trapped within the jumper. The body the temperature from our body is transferred to our clothing keeping the air and wool warm.
Name 3 fossil fuels?
Coal, oil, gas - formed millions of years Go from fossilsed remains eg sea creatures, trees. They are non renewable.
What does non renewable mean?
You cant use them again
What is radiation?
Transfer of energy by electromagnetic waves eg light, infrared, microwave