Changes of EnergyChanges of Energy

Energy TransfersEnergy Transfers

Energy can be transferred from one object Energy can be transferred from one object to another.to another.

It is a transfer if the same It is a transfer if the same formform of energy is of energy is in both objects.in both objects.

For example, heat energy is For example, heat energy is transferred from the element transferred from the element in the stove to the pot when in the stove to the pot when you are cooking.you are cooking.

Energy ConversionsEnergy Conversions

A conversion is a change from one form of A conversion is a change from one form of energy to anotherenergy to another

For example, when you turn the light on, For example, when you turn the light on, the electricity makes the light glow. This is the electricity makes the light glow. This is a conversion from electrical energy to light a conversion from electrical energy to light energy.energy.

Conservation of EnergyConservation of Energy

The Law of Conservation of energy states:The Law of Conservation of energy states:

You cannot create or destroy energy, it can only be changed You cannot create or destroy energy, it can only be changed from one form to another.from one form to another.

So all the energy that is in an object must So all the energy that is in an object must end up somewhere!end up somewhere!

For example, the food you eat contains For example, the food you eat contains chemical potential energy. chemical potential energy. - Some of this energy is converted into kinetic energy, - Some of this energy is converted into kinetic energy,

when you move. when you move. - Some is converted into sound energy, like a gurgling - Some is converted into sound energy, like a gurgling

stomach. stomach. - Some is converted into the heat energy that keeps you - Some is converted into the heat energy that keeps you

warm. warm. - Some energy is used in chemical reactions in your body. - Some energy is used in chemical reactions in your body. - Any energy that is left from this is stored in another - Any energy that is left from this is stored in another

chemical called fat.chemical called fat.

““Energy Chains”Energy Chains”

We can summarise transformations and We can summarise transformations and conversions using arrows.conversions using arrows.For example, if you are describing the For example, if you are describing the energy changes involved in throwing a ball energy changes involved in throwing a ball in the air, you might write:in the air, you might write:

Chemical potential kinetic gravitational potential kinetic