So we know that we get our energy from the food we eat, does this mean that food contains energy? 

Food contains a particular sort of energy that our bodies can turn into movement energy, sound energy when we speak and heat energy to keep us warm.  We have to eat everyday to make sure that we have enough energy to stay alive and healthy so where does all the energy go?

Wood contains energy, we cant see the energy in a block of wood because it doesn't move, it doesn't light up, you cant hear and it doesn't feel hot so it cant be giving off any heat.  If we want to get the energy out of the wood we set it on fire.  We can then see the energy as light and we can feel the warmth which is the heat energy.  The fire will burn until the energy in the wood has been changed into heat and light, we sometimes have small fires in our houses to keep us warm.  We keep the doors and windows closed to keep the heat inside, if you open the front door the heat escapes outside and you cant get it back, it doesn't disappear it just spreads out everywhere until you can't tell that its there at all.

Food contains the energy that we need to live.  Food is our fuel!

Wood contains energy that we use to make heat and light.  Wood is the fuel for the fire!

In fact everything contains energy, it is easy for us to use the energy in a block of wood but its not so easy to make use of the energy in a brick or bucket of cold water.

We now know that we can release energy from some materials by burning them.  Most of this energy is turned into heat which is brilliant for keeping us warm but how can we use it to make a car move?