Energy Transfers Flashcards
Give 5 energy stores
Chemical Kinetic Gravitational Elastic Thermal Magnetic Electrostatic Nuclear
Give 3 energy transfers
Mechanically
Electrically
By heating
By radiation (light and sound)
What is the conservation of energy
This means there is the same amount of energy after a transfer as there was before it.
How do you find how efficient it is
Useful energy output
Efficiency = ———————————- (x 100)
Total energy input
Efficiency is always less than….% because of the unwanted energy always produced
100%
Energy is often lost to heat due to…..
Friction
What input of energy does a battery have
Chemical
What is the output of an engine
Kinetic
Give 2 objects that need light as an input
Solar Panels
Plants
What state is only possible for conduction
Solid
Conduction takes place by heat energy passing from….to……but the material itself does not…..
Particle to Particle
Move
Which type of solid is very good at conduction
Metals
What states of matter can convection only happen in
Liquids and gasses
What happens when a liquid or gas is heated
It expands
Give the process of convection (5 stages)
The liquid or pass is heated, and expands
Its volume increases
So its density decreases
So it rises
Cooler, more dense fluid sinks to take its place producing convection currents
The…..does not rise. Instead the…….do
Heat
Substances
What is different about radiation to the other heat transfers.
It can travel through a vacuum (needs no particles)
What type of radiation does it use
Infa-red
Give an example of radiation as a heat transfer
The heat from the sun to the Earth
Can radiation happen in all states
Yes
What do convection,, conduction and radiation all do the same
TRANSFER ENERGY!
Which surface colour absorbs the most heat
Matt black
Give 2 examples of convection in everyday life
Radiator
Chimney
What does insulation do
Prevents energy loss (heat loss)
What do insulating materials do
These are non-metals such as plastic and air to reduce the conduction of heat
What colour is best for insulating
What as it is a poor absorber and emitter of heat radiation.
By insulating, how does it help to have small pockets of air
This means that conduction can’t take place
