GCSE Edexcel Physics 3.1 - Conservation of Energy

Change in G.P.E (J) = mass (kg) x gravitational field strength (N/kg) x change in height (m)
ΔG.P.E. = mgΔh

A change in height

When an object's height increases

When an object's height decreases

Kinetic Energy (J) = ½ x mass (kg) x velocity² (m/s)
K.E. = ½mv²

When an object is moving (has some velocity)

When the object accelerates (when velocity increases)

When the object decelerates (when velocity decreases)

A spring / rubber band is stretched or compressed

Objects with charge (like protons or electrons) interacting

Magnets interacting

Energy in muscles
Fossil fuels
Batteries

Radioactive isotopes (used in nuclear reactors)

All objects have energy in their thermal store
The hotter the object, the more energy in its thermal store

Energy cannot be created or destroyed, it can only be transferred

Energy in a closed system remains constant

Energy is transferred from the kinetic store to the gravitational store
(The object slows down but gains height)

Energy is transferred from the kinetic store to the gravitational store
(The object slows down but gains height)

Energy is transferred from the kinetic store to the obstacle’s kinetic store or elastic store
(Object slows down but obstacle accelerates or collision causes deforming)

Energy is transferred from the person’s arm’s chemical store to the kinetic store of the ball
(Energy in the muscles is used up but the ball accelerates)

Energy is transferred from the chemical store of the fuel to the kinetic energy of the rocket
(Fuel is burned but rocket accelerates)

Energy is transferred from the car’s kinetic store to the thermal store of the brakes
(Car slows down but brakes heat up)

Energy is transferred from the thermal store of the heating element to the thermal store of the water

Energy is transferred from the object’s gravitational store to kinetic store
(Object loses height but accelerates)

Energy is transferred from the object’s gravitational store to the kinetic store
(Object loses height but accelerates)

Energy is transferred from the chemical store of the fuel to the kinetic store of the car
(Fuel is burned and car accelerates)

Person has energy in kinetic store.
As they land on trampoline energy is transferred to the elastic store of the trampoline,
and then back to the kinetic store of the person as they bounce back up.
As the person goes up, the energy in their kinetic store is transferred to their gravitational store.
They start falling again and energy is transferred back to the kinetic store, restarting the process.

Nothing changes so no energy is transferred

Energy is transferred between energy stores within the system
There is no change in total energy in the system