aqa physics - energy stores and systems

what happens to energy when it is transferred?

it is never used up, only transferred between different energy stores

what are the four ways energy can be transferred?

mechanically (force doing work), electrically (moving charges), by heating, or by radiation

where is energy stored when transferred to an object?

in one of the object's energy stores

name all eight energy stores

thermal, kinetic, gravitational potential, elastic potential, chemical, magnetic, electrostatic, nuclear

what is a system?

a single object or a group of objects you are interested in

what happens to energy when a system changes?

it is transferred into or out of the system, between objects, or between different energy stores

what is a closed system?

a system where neither matter nor energy can enter or leave

what is the net energy change in a closed system?

always zero

how is energy transferred in a boiling kettle?

electrically to the kettle's heating element, then by heating to the water's thermal energy store

what is another way to describe energy transferred?

work done

when is work done?

when current flows in a circuit or when a force moves an object

how is energy transferred when a ball falls?

gravitational force does work, transferring energy from the ball's gravitational potential energy store to its kinetic energy store