Conduction, Convection & Radiation
The past studies of energy have all been about heat, and some of its uses. This article introduces some other concepts related to heat in order to prepare you for a 5th grade science project which will allow you to harness the sun's heat, and heat power in order to cook.
We already know that heat can be transferred from one object to another. This transfer is called conduction. A hot object can transfer its heat to a cooler object. When we rub our hands together and generate heat, the heat in our hands can be transferred to our cheeks when our hands touch our cheeks. Conduction can happen in and among any of the states of matter. Can you think of what objects are good conductors of heat?
Radiation is the transfer of heat through waves of electromagnets. These electromagnetic waves are emitted by one object and can be absorbed by another. The heat energy from the object which emits radiation travels in multiply directions and in straight lines, similar to how the sun's rays appear to travel. Radiation is used for many things in modern society, including surgery, and attempts to cure people of cancer and other diseases. It is difficult to come up with a 5th grade science project that demonstrates radiation, and experiments using this require a lot of safety precautions and experience.
Apart from conduction and radiation, the last most popular form of transferring heat is convection. Convection transfers heat by diffusing it. For an easy example you can find in your home, look at your toaster. Most toaster ovens these days are convection toaster ovens. It generates heat in order to cook, but the way it transfers the heat to the food is what we call convection. This means that the generated heat is diffused throughout the system in order to transfer itself into what we're toasting. If you put a premade or store bought hashed brown into a convection toaster oven, you will find that the hashed brown cooks evenly on all sides and with the same amount of crispness. This is because the heat of the toaster was diffused through the hashed brown in an even manner.
The process of convection is what we will be using for our 5th grade science project regarding heat. In the projects section, you will find out how to make your own convection oven, and actually cook or bake with it.