Energy Stores & Systems Flashcards
What is a system?
An object or group of objects you are interested in
What is a closed system?
Where neither matter nor energy can enter or leave
The net change in total energy is always 0
The 8 energy stores are:
Thermal, kinetic, gravitational potential, elastic potential, chemical, magnetic, electrostatic, nuclear
Energy can be transferred between stores:
Mechanically
Electrically
By heating
By radiation
Energy can be transferred mechanically:
An object moving due to a force acting on it e.g. pushing, pulling
Energy can be transferred electrically:
A charge (current) moves through a potential difference e.g. charges moving round a circuit
Energy is transferred by heating:
Energy transferred from a hotter object to a colder object e.g. heating a pan of water on a hob
Energy is transferred by radiation:
Energy transferred by light/sound waves
Work done is
Energy transferred from one store to another by forces or when a current flows
Work done formula
Work Done = force * distance
Principle of conservation of energy:
Energy cannot be created or destroyed - it can only be transferred from one store to another
Kinetic energy
Energy stored in moving objects
Kinetic energy formula
Ek = 1/2mv^2
Elastic Potential energy
Energy stored in a stretched spring
Elastic Potential energy formula
Ee = 1/2ke^2
Assuming limit of proportionality hasn’t be exceeded
