Science projects are an effective way of sparking interest among primary school students intimidated by the subject. These projects not only teach participants something new, they also develop additional skills, such as word processing, library and online research, mathematical analysis and photography. In addition, putting together projects related to heat conductivity and thermal insulation or other science projects for a science fair helps sharpen hand-to-eye coordination, engenders self-confidence and gives the student public speaking practice while presenting the project to an audience.
Other People Are Reading
Heat travels in three different ways -- conductivity, convection and radiation. Conductivity describes heat travelling through a solid; convection relates to heat travelling through gasses and liquids; and radiation is heat travelling through an empty space, such as a partial vacuum. All molecules vibrate to a greater or lesser extent. When heat is applied to a solid object, molecular vibration within the solid escalates and produces heat energy. This causes individual molecules to bump against their neighbours, thereby transferring heat energy progressively through the solid via friction. For example, stirring hot tea with a cold teaspoon will eventually warm up the handle.
Speaking of teaspoons, silver is the most conductive metal known; therefore, apart from checking the hallmark, there’s a simple way of telling whether a spoon is made of solid silver or whether it’s silver plated. Place a dab of butter on both handles and press a grain of rice into the butter. Stand both spoons in a mug of boiling hot water and watch both grains of rice. Since the plated spoon is usually made of brass covered with a thin layer of silver, the solid silver spoon will transfer heat to the handle quicker than the plated spoon. Therefore the dab of butter on the solid silver spoon will always melt first, causing the grain of rice to fall off well before the butter on the plated spoon melts.
Insulating materials retard the flow of heat energy by reducing heat loss or gain. For example, a fleece lined jacket will protect you from frostbite and keep you comfortable during harsh winter weather. In addition a loose woollen garment, as worn by Bedouins in the Sahara desert, will keep you relatively cool during hot weather.
Insulation also protects against burning. For example, wearing oven gloves protects your hands while removing a baking pan from a hot oven, and plastic or wooden utensil handles prevents burning while stirring or ladling out hot soup or stew. Here’s another example: Insulated refrigerator and freezer lining keeps food fresh by preventing refrigerated air from escaping. To demonstrate this, place one tray of ice cubes on the table and the other inside an insulated polystyrene cooler box. Wait an hour or two. When the ice in the table mounted tray melts, you’ll find that the ice cubes stored in the cooler box are still frozen solid.
Our ancestors used insulation to good effect by inventing "hay box cooking," thereby conserving their stack of firewood. Try it by first dropping chopped carrots, potatoes, cabbage and a ham bone or cubed stewing mutton into a pot of boiling water. Add seasoning and replace the lid. Immediately stand the pot in a cardboard box containing a thick layer of dried straw. Pack more straw closely around and on top of the pot. Close the lid and let your hay box stand for five to eight hours. Remove the lid, and you’ll find a pot full of rich savoury stew.
- 20 of the funniest online reviews ever
- 14 Biggest lies people tell in online dating sites
- Hilarious things Google thinks you're trying to search for