Heat
Explanation
Heat is the energy transferred or being transferred between two systems at their boundaries. The symbol Q is used to represent heat in general. Heat transfer occurs when there is a difference in temperature between two or more bodies. Heat is transferred by physical contact of the bodies called conduction, by emitting electromagnetic waves by the process of thermal radiation, and by convection where the heat is transferred from a solid wall to the fluid medium.
Frequently Asked Questions
How heat transfer is different from other forms of energy transfer like work transfer?
Heat transfer is a boundary phenomenon that arises from the difference in temperature of two systems. On the other hand, the work transfer is the transfer of work in the form energy from the system to the surroundings or vice versa due to other property differences. This includes all the displacement, electrical, and other mechanical works. Similar to heat transfer, work transfer is also a boundary phenomenon. In other words, heat transfer and work transfer are both energy interactions where the former is due to the temperature difference in the system and surroundings. So technically, heat is the energy transferred between the molecules and the work is the energy transferred to the object's motion.