Study of the techniques and methods adopted to transfer heat energy is known as ‘Heat Transfer’. Heat energy can be transferred from one body to the other or from one location in a body to the other. The properties of the matter involving heat transfer and measurement are known as ‘Thermal Properties of Matter’ Heat Transfer ![]() You can download Thermal Properties of Matter Sheet by clicking on the download button below The temperature of a substance is a physical quantity that measures the degree of hotness or coldness of a body. It is measured in degree Celcius (☌) or Kelvin(°K). The temperature of a body is the measure of the amount of heat content possessed by it. Ideal Gas Equation and Absolute Temperature.In CGS system, however, heat is measured in ‘Calorie’ (Cal.) where 1 Calorie = 4.186 J Browse more Topics under Thermal Properties Of Matter The SI unit of heat energy is Joule abbreviated as ‘J’. Heat energy of a body can also be defined as a form of energy that can be transferred from one body to the other or within the body itself with a temperature difference and can be generated by a body at the expense of other forms of energy. Melting point, Boiling point) do the molecules or atoms free themselves from interatomic forces of attraction and conversion of a state i.e. As a result, when this energy reaches a threshold ( eg. This kinetic energy builds up on a macro level as more and more energy is supplied to these molecules of the substance. As they vibrate they transfer their energy to the surrounding molecules causing them to vibrate as well. Molecules of a substance vibrate at their positions either fixed or not when energy is supplied to them. It derives its origins at the molecular scale. Matter exists in 4 forms which are solid, liquid, gas and plasma. Each method has unique and interesting characteristics, but all three do have one thing in common: they transfer heat solely because of a temperature difference Figure 1.We know that matter is defined as anything which has a mass and occupies some space. We examine these methods in some detail in the three following modules. Heat transfer by convection also occurs through cold air entering the room around windows and hot air leaving the room by rising up the chimney. Heat transfer also occurs through conduction into the room, but at a much slower rate. Radiation is responsible for most of the heat transferred into the room. In a fireplace, heat transfer occurs by all three methods: conduction, convection, and radiation. A less obvious example is thermal radiation from the human body.įigure 1. An obvious example is the warming of the Earth by the Sun. Heat transfer by radiation occurs when microwaves, infrared radiation, visible light, or another form of electromagnetic radiation is emitted or absorbed.This type of transfer takes place in a forced-air furnace and in weather systems, for example. Convection is the heat transfer by the macroscopic movement of a fluid.(The matter is stationary on a macroscopic scale-we know there is thermal motion of the atoms and molecules at any temperature above absolute zero.) Heat transferred between the electric burner of a stove and the bottom of a pan is transferred by conduction. Conduction is heat transfer through stationary matter by physical contact.Yet every process involving heat transfer takes place by only three methods: So many processes involve heat transfer, so that it is hard to imagine a situation where no heat transfer occurs. We can control rates of heat transfer by choosing materials (such as thick wool clothing for the winter), controlling air movement (such as the use of weather stripping around doors), or by choice of color (such as a white roof to reflect summer sunlight). Heat transfer may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice chest. Whenever there is a temperature difference, heat transfer occurs. Discuss the different methods of heat transfer.Įqually as interesting as the effects of heat transfer on a system are the methods by which this occurs.
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