If we look closely, we can say with certainty that life on Earth is directly linked to a form of energy necessary for the survival of all living beings. This form of energy is known as heat. In fact, we see that the Sun heats our planet just the right amount in order to ensure that the diverse forms of life are preserved. But what if the Earth were a little farther away or a little closer to the Sun, what would happen? If that happened, maybe the story about survival on Earth would be different, or maybe there was no life at all.
So, if we manipulate the heat we have the possibility to produce heating, cooling and changes in the physical state of bodies. We are fully convinced that bodies, materials, etc., are made up of different particles and these particles are in constant motion. The agitation of the particles that make up a body is associated with an average kinetic energy, that is, energy of movement, which is called Thermal energy. Therefore, we can say that the higher the temperature of a body, the greater the agitation of its molecules (or particles) and, therefore, the greater its thermal energy.
In our studies related to Thermodynamics, we saw that when we put two bodies of different temperatures (a cold body and a hot body) in the same container, isolated from the middle, over time we will notice that the temperatures will equalize. This fact happens because a body with higher temperature, that is, greater thermal agitation, transfers heat to the lower temperature body, that is, it transfers Thermal energy.
THE Thermal energy in motion (transit), caused by the difference in temperature between two bodies, is called heat.
In Physics we always make use of measurement units, which are actually used to characterize a physical quantity, therefore, when it is energy (heat) the unit of measure we will use is the joule, represented by the capital letter J or we can also use the calorie (lime). The value between these two units was defined as follows:
1 cal=4.186 J ⇒ 1 J=0.239 cal
By Domitiano Marques
Graduated in Physics
Source: Brazil School - https://brasilescola.uol.com.br/fisica/relacao-entre-energia-termica-calor.htm
