The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:
You must have experienced the heat in summers when you are wearing full clothes. Heat is a form of energy that makes us experience the rising temperature and react to it. It is a basic form of energy required on the earth for survival. If you take examples of polar bears found in Antarctica, they have thick fur that helps them remain warm even in the coldest of places. Hence, heat is necessary for the survival of organisms.
Heat is transferable. The increasing temperature associated with the increase in heat is responsible for the atoms to vibrate more vigorously. These vigorous vibrations are transferred from one part of the body to others. Similarly, the vibrations move to the next section of atoms and continue to travel to the extreme, meanwhile conducting heat through the complete solid.
Heat energy flow is multidirectional. The vibrating atoms can be in touch with all their adjacent atoms and facilitate heat energy flow. The phenomenon of hot and cold is associated with this heat energy. When the temperature is high, then we feel hot and vice-versa.
There is also the phenomenon of sublimation, or latent heat, where the substance absorbs heat without changing its temperature. Hence, we cannot say that giving heat always increases the temperature. In these cases, heat energy is utilised to transform the state of the material. For example, if we supply heat to ice, then instead of increasing the ice temperature, it is utilised in the phase transformation of ice in the water.
In latent heat, the heat energy remains hidden in another form inside the material. For example, suppose we heat a container of water. It gets converted into steam which holds the heat energy that was transferred to the water while boiling.Since heat is a form of energy that follows the thermodynamics laws, heat energy can be transformed into other kinds of energy. For example, in cars, pistons’ heat energy is used as a mechanical force to drive the car’s motors. Similarly, in thermal power stations, heat energy in the form of coals are converted into electrical energy.
We use a physical quantity to measure heat energy. For measuring temperature, you can use a laboratory thermometer that runs on the mercury levels. Temperature can be written in different forms such as Kelvin, Celsius and Fahrenheit. All these three elements of measuring temperature are interchangeable and follow a fixed rule. Kelvin is the SI unit of temperature.
Since heat is a form of energy that follows all the thermodynamic laws, it can be transferred to different areas. There are three conventional ways of heat transfer –
Summers are hot, and winters are cold. Hence, we need certain clothes to keep us cool in the summers and keep us warm in the winters. For summers, we use cotton clothes to facilitate the evaporation process from the clothes surface quickly and hence making us cool. In winters, we wear woollen clothes that trap heat energy and don’t let our body heat pass out. Thus, we have a layer of heat around our body that keeps us hot in the winters.
Heat is a form of energy found in every part of our world. It obeys the Laws of Thermodynamics and can be transformed into different kinds of energy. For example, heat energy can be transferred to mechanical energy or electrical energy. There are three ways of transferring heat from one place to another: conduction, convection and radiation. Heat is essential for the survival of organisms on this planet.
On the MSVgo app, you can check the different kinds of heat and their influences on earth. You can also learn about the different types of heat transfer mechanisms established in thermodynamics.