Video Transcript

Hello, my name is Walter Unglaub, and this is 3 processes of heat transfer thermodynamics. So in thermodynamics there's essentially 3 primary methods in which heat can be transferred from one object to another. The first is known as conduction and conduction is a process that involves 2 materials that are in contact with each other so material 1 and material 2 are in contact with each other and they each have different temperatures and because they're touching this heat will be transferred directly from one object to another depending on what the relative temperatures are. So in this case we have atoms that are and molecules that are transferring their kinetic energy between each of the other molecules and atoms that are neighboring and this is one of the basic, one of the most basic methods in which heat is transferred because this entire system wants to reach equilibrium at some time later and to do that we need to transfer all the temperature between the particles. So this is one method in which heat is transferred at thermodynamics. So second method is convection. So convection operates under a similar premise however here we have some material like a slab of material and we have a fluid like for example like water that is made up of many water molecules and the way heat is transferred would be due to a difference in temperatures is you'll have each of these molecules bump up against the surface and make contact momentarily and so temperature the heat that is contained in the kinetic energy of the particles that make up the material will be transferred into the, into the molecules of the fluid that is rushing past this material and this will serve to increase the kinetic energy of the particles if the average temperature of the material is higher than that of the liquid or if it's the other case then the kinetic energy of the molecules will be imparted onto the surface in which the fluid makes contact with the material. So this process is known as mass transfer and it's often exploited in a lot of engineering to, to transfer energy and heat in away to facilitate whatever apparatus one is using such as a power plant to cool things down. Finally a third method to transfer heat and thermodynamics is known as radiation and radiation is a physical process by which some hot or thermal material emits light such as IR which is infrared or thermal light, thermal heat or sometimes x-rays for example and another object will absorb that energy because light has an energy equivalent to it's momentum times the speed of light. So since the mass is non-existent in the case of the photon one can think of the photon as a quanta or packet of energy and this energy can be directly absorbed by another material via absorption thus increasing the total thermal energy of the second object. So radiation is a third method for transferring heat in thermodynamics and these are the basic 3 and there's a lot of equations involved and many different physical systems that involve multiple methods of transferring heat. My name is Walter Unglaub and this is 3 processes of heat transfer in thermodynamics.