12/12/11
Real-Life Applications of Heat – Heat Energy and Transfer
Abstract: This reflective essay addresses heat energy and transfer and how they are used in real-life applications – from the natural world to modern human technology. This essay shows that heat is very important to nearly everything in life and how it is used nearly everywhere.

12/12/11

“Heat energy (or just heat) is a form of energy which transfers among particles in a substance (or system) by means of kinetic energy of those particles. In other words, under kinetic theory, the heat is transferred by particles bouncing into each other (physics.about.com).” Heat is thermal energy. When you add heat to a substance, you are adding energy. Heat transfers throughout our environment all the time. Wherever you are, you are aware of things that are warm or cold. When deciding what we will where for the day, we pay attention to how hot or cold it is outside. Heat is everywhere and can be transferred through three processes known as conduction, convection, and radiation.
“Conduction occurs when two object at different temperatures are in contact with each other. Heat flows from the warmer to the cooler object until they are both at the same temperature. Conduction is the movement of heat through a substance by the collision of molecules. At the place where the two object touch, the faster-moving molecules of the warmer object collide with the slower moving molecules of the cooler object. As they collide, the faster molecules give up some of their energy to the slower molecules. The slower molecules gain more thermal energy and collide with other molecules in the cooler object. This process continues until heat energy from the warmer object spreads throughout the cooler object. Some substances conduct heat more easily than others. Solids are better conductor than liquids and liquids are better conductor than gases. Metals are very good conductors of heat, while air is very poor conductor of heat (coolcosmos.ipac.caltech.edu).”
Cooking: Have you ever cooked on the stove? Whether you are cooking eggs or steaks or hamburgers, when you place that pan on the stove-top you are applying conduction. The heat from the hot stove-top transfers from the stove to the pan and is used to cook our food.
A Cup of Coffee: When a ceramic coffee cup is filled with hot tea or coffee the heat transfers from the liquid into the material of the cup. If you touch the ceramic cup shortly after pouring hot coffee in it, you will notice it is really hot due to conduction. The handle on the cup will not be as hot though because not all heat will be at this point. This is why almost all ceramic cups have handles on them.
Soldering: Conduction is also used in the creation of nearly all electronics when they solder it. Soldering is a great example of heat transfer through conduction. When they solder electronics, the heat transfers from the soldering tool to where it is applied on the device.
Iron: When you are using an electronic iron you also use conduction. The iron heats up and when touched to the cooler object (shirt or pants) the heat is transferred to it. With the applied heat we can eliminate wrinkles in clothing we wear.
“Convection occurs when warmer areas of a liquid or gas rise to cooler areas in the liquid or gas. As this happens, cooler liquid or gas takes the