Physics 171 – Professor Reeves
Conduction, Convection, and Radiation: Methods of heat transfer
Conduction, Convection, and Radiation: Methods of heat transfer.
There are three different types of heat transfer we often discuss in physics. This paper uses example of each type of heat transfer; conduction, convection, and radiation. When breaking down conduction we understand it is the physical transfer of heat. Two objects are touching and the heat from one object transfers to the other object to warm it. In convection we understand it is the flow of matter that moves the heat. Matter is warmed, moves away from ...view middle of the document...
The big question is what happens when the object are two different temperatures. That is where heat transfer comes into the picture. When one object has a lot of energy or a higher temperature and it is next to an object that has less energy, a lower temperature, the heat or energy will transfer from the object with the higher energy to the object with lower heat until the two objects have reached equilibrium. This heat transfer and the methods of it are what we are going to talk about today.
Conduction is the first method of heat transfer we will discuss. This is probably the simplest form of heat transfer and one we certainly see and likely even use on a daily basis. Conduction is defined as the process by which heat energy is transmitted through collisions between neighboring molecules (https://www.ucar.edu/learn/1_1_2_6t.htm).
To start with conduction we start with the basics of what everything is made up of, particles or atoms. Everything including ourselves is made up of tiny pieces know as atoms. These atoms exist in different states depending on the material they are a part of. For example, in a gas such as the air we breathe the atoms are far apart. They float around and have a lot of space between each other. In a liquid the atoms are closer together, they are in contact with each other all of the time but they don’t have a strong bond. Since they don’t have a strong bond they are able to be manipulated easily and will take the shape of whatever they are poured into. The final state atoms exist in is a solid. In a solid state the atoms exist within the structure and although they can move they don’t move very far, in fact all they really can do is wiggle back and forth a little bit; otherwise they are in a fixed state. They need to remain this way in order for the object, say a chair or cup, to maintain its structure and shape.
Conduction is the movement of heat from one molecule to another and so on and so forth until a thermal equilibrium has been attained. The first example of conduction that many of us see every day is when we poor coffee into our favorite coffee mug. Conduction is taking place right at the barrier of where the coffee and the mug touch. The hot coffee’s particles have a lot of energy so they are moving really fast. At that barrier the particles of the coffee mug don’t have as much energy, so the particles of the coffee collide with the particles of the coffee mug. During these collisions energy or heat is transferred from the particles of the coffee to the particles of the coffee mug. The particles of the coffee will lose some of their energy and the particles of the coffee mug will gain some energy. Now think of the particles of the coffee mug being all stacked up in rows. In this case, the energy from the coffee interacts with the first row, but then once the first row gains energy and those particles start vibrating, they start to transfer energy to the second row. This...