This is an introduction to energy stores and pathways for GCSE Physics.
Key idea – Energy shifts between stores via a pathway.
You need to know the possible stores and pathways and be able to apply these to examples.
Energy can be stored in different ways. These are the 8 possible energy stores:
– chemical (e.g. fuel + oxygen)
– kinetic (in a moving object)
– gravitational (due to the position of an object in a gravitational field)
– elastic (e.g. in a stretched or compressed spring)
– thermal (in a warm object)
– magnetic (in two separated magnets that are attracting, or repelling)
– electrostatic (in two separated electric charges that are attracting, or repelling)
– nuclear (released through radioactive decay, fission or fusion.
Energy shifts between stores along a pathway. These are the 4 possible pathways
– mechanical (when a force acts and something moves)
– electrical (when a current flows)
– by heating (because of a temperature difference)
– by radiation (a wave such as light, microwaves or sound)
Example of energy shifting from one store to another
Take the example of a car moving along, but braking and slowing down
The system is the car moving.
Energy is in the kinetic store to start with.
When it slows down, energy shifts from the kinetic store to thermal store of energy due to friction between wheels and brakes.
Energy shifts via the mechanical pathway.
The brakes do mechanical work on the car and this causes energy to shift from the kinetic store to the thermal store.
When the car has completely stopped, all of the energy is in the thermal store.
Try the quick check quiz on energy stores below: