What is heat ? If we look at the definition of physics, it is the energy that, through the movement of different particles, such as molecules and atoms, is transferred from one body to another. It is therefore a source of energy that flows from an object that is at a higher temperature to another that is colder . The transfer speed basically depends on the temperature difference between one object and another.
There are three different ways that heat can be generated, and they are as follows:
- Driving: it is the easiest to understand. It consists of the transfer of heat between two points of a certain object that is at different temperatures. In this case there is no transfer of matter between them.
- Radiation: the heat emitted by a body due to its high temperature is known as such. It is transferred by electromagnetic waves. There is no need for direct physical contact between the power source and the receiver.
- Convection: and, finally, the form of propagation that occurs in fluids, both in liquid and gaseous states by a real movement of matter. It occurs when areas of hot fluid, whose density is lower, rise to the regions of cold fluid, in such a way that the latter, which has a higher density, descends and takes the place of the hot fluid.
Heat measurement
The amount of heat energy that is transferred is calculated, and the result is expressed in calories . This is an unofficial, but fully accepted unit of measurement that reflects the amount of energy it takes to raise the temperature of a gram of water from 14.5 degrees to 15.5 degrees Celsius. In the International System of Units, the unit of energy is called the joule. One calorie is equivalent to 4,184 joules.
Is there cold?
In the fall and winter months we have all felt cold at times. But the truth is that, as scientists say, cold as such does not exist . There is no way to measure how cold an object is, only its temperature. What makes us feel cold is the loss of energy from the atoms that make up the object in question.
