Heat is the process by which kinetic energy is transferred by an energy source from one medium to another. Radiation, conduction, and convection are the three different mechanisms by which this energy can be transferred. Heat is a type of energy that causes any substance’s temperature to change. Heat energy is calculated by using the Heat Formula. Practising questions will help students retain Heat Formula for a long time in their memory.
The average molecular kinetic energy of that substance is also related to temperature. Different scales are used to measure temperature, including Celsius (C), Fahrenheit (F), and Kelvins (K). So, to put it simply, temperature refers to how hot or cold an object is. The energy that moves from a hotter object to a cooler object is known as heat, on the other hand. It is important to go through the derivation of the Heat Formula. Each step used in deriving the Heat Formula is important. Students having any difficulty with the Heat Formula can take help from Extramarks.
Thermal expansion may occur as a result of heat. This phenomenon occurs in gases, liquids, and solids. The majority of materials expand as temperatures rise. For instance, a hot air balloon rises and expands as a result of the heated air inside. Every time the temperature rises, thermal expansion happens as a result, and devices can make use of this idea.
When two objects are kept in direct contact, heat is transferred by conduction. Additionally, one has a higher temperature than the other. As a result of the tendency for temperatures to equalize, heat conduction involves the transfer of kinetic energy from a warmer medium to a cooler one. When two material media or objects are in direct contact and one of them has a higher temperature than the other, heat by conduction occurs. As a result of the tendency of the temperatures to equalise, kinetic energy is transferred from the warmer medium to the cooler one during the process of heat conduction. An illustration would be putting a cold body in a hot bath.
When a liquid or gas moves, it transfers energy from a warmer area to a cooler area, creating heat by convection.
The tendency of warm air to rise and cool air to fall, which equalises the air temperature inside a room with a hot stove, is a good illustration of convection. The transfer of kinetic energy from the inner core through the outer core and mantle to the crust is thought to occur inside the Earth through heat convection, along with conduction. In this case, the outer core and the mantle exhibit long-term liquid-like behaviour.
What is the concept behind heat?
Heat is energy that is transferred into or out of a thermodynamic system via a mechanism involving either the corresponding macroscopic properties or microscopic atomic modes of motion. The transfer of energy through thermodynamic work or mass transfer is not included in this descriptive description. The internal energy difference between a system’s final and initial states, less the work that was done during the process, is how heat is quantitatively defined as being involved in a process.
Solved Examples It is necessary to practice questions related to the Heat Formula. All the examples involving Heat Formula can be practised with the help of the pedagogical resources provided by Extramarks. Revising Heat Formula is important as well. All the difficult questions related to the Heat Formula need to practise more.