Energy transfers Flashcards
(20 cards)
Joule
J
what are the 8 energy stores?
Chemical
Kinetic
gravitational
Elastic
Thermal
Magnetic
Electrostatic
Nuclear
What are the 4 main energy transfers?
Mechanically
Electrically
By heating
By radiation
Kinetic
Moving objects have energy in their kinetic store.
Gravitational
Objects gain energy in their gravitational potental store when they are lifted through a gravitational field.
Elastic
Objects have energy in their elastic potential store if they are stretched, squashed or bent.
Magnetic
Magnetic materials interacting with each other have energy in their magnetic store.
Electrostatic
Objects with charge (like electrons and protons) interacting with another have energy in their electrostatic store
Chemical
Chemical reactions transfer energy into or away from a substances chemical store
Nuclear
Atomic nuclei release energy from the nuclear store during nuclear reactions
Thermal
All objects have energy in the thermal store the hot of the object, the more energy it has in this store.
Mechanical working
When a force acts on an object (e.g pulling, pushing, streching, squashing.)
Electrical working
A charge moving through a potential difference (e.g current)
Heating (by particles)
Energy is transferred from a hotter object to a colder one (e.g conduction)
(Heating by) radiation
Energy transferred by electromagnetic waves (e.g visible light)
equation of efficiency
Efficiency = useful energy out / total energy in
Definition of efficiency
A way of saying how much energy is transfered in useful ways by a machine
Energy is :
- the ability to do work
- the ability to cause motion
- the ability to create change
- you cannot create or destroy energy, it can only be transferred
Energy transfers:
In all system changes energy spreads out (disapates)
Every day example
Fire:
Input energy store - thermal
Useful energy store - thermal
Wasted energy store - chemical
Energy transfer pathways involved - radiation
