I.1.1. The physical phenomenon
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A physical phenomenon (physical process) occurs when at least one of the physical properties that characterize a body changes over time.
🔦 Remark
Due to a physical phenomenon, the body does not change its substance.
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Physical phenomena classification.
1. Mechanical phenomena.
- related to the movement of the bodies (the body changes its position towards a landmark);
- elongation of a spring (the spring increases its length) / compression of a spring (the spring decreases its length) also called ** elastic deformations **;
- breaking, cutting also called plastic deformations.
2. Thermal phenomena. These are the phenomena related to the change of the thermal state of a body:
- heating (the body raises its temperature) / cooling (the body lowers its temperature);
- dilation (the body increases its volume, by heating) / contracting (the body decreases its volume, by cooling);
- melting (body changes from solid state to liquid state, by heating) / solidification (body changes from liquid state to solid state, by cooling);
- vaporization (body changes from liquid to gaseous state by heating) / condensation (body changes from gaseous to liquid state by cooling);
- sublimation (body changes from solid to gaseous state by heating) / desublimation (body changes from gaseous to solid state by cooling).
3.Electrical phenomena. There are those phenomena related to:
- electrification of bodies (the body is charged with electrical charges);
- passing the electric current through a circuit, etc.
4.Magnetic phenomena. There are those phenomena related to:
- the attraction between magnet and ferrous metals (iron, nickel, cobalt);
- the attraction and repulsion between two magnets.
5.Optical phenomena. There are those phenomena related to:
- light reflection (return of light in the first environment, with change of direction);
- refraction of light (passage of light in the second medium with change of direction);
- rainbow formation etc..
6. Acoustic phenomena. These are those phenomena related to:
- propagation of sound;
- reflection of sound.