# What is irreversible or reversible with examples

## Energy devaluation

Observe the processes indicated in the three animations and judge whether they can actually take place in this way. Also think about which energy conversions take place.

Jump into the water

• The first part of the animation can take place as shown. Potential energy is converted into internal energy.

• Experience has shown that the second part of the animation is not observed, but it would be possible due to the law of conservation of energy. During this process, the internal energy would be converted into mechanical energy (positional energy).

Welding system

• The first part of the animation can take place as shown. There is a conversion of electrical energy into internal energy.

• The second part of the animation is not observed, but would be possible due to the law of energy conservation. During this process, the internal energy would be converted into electrical energy.

Tea in cup

• The first part of the animation can take place as shown. There is a conversion of internal energy at high temperature into internal energy at low temperature.

• The second part of the animation is not observed, but would be possible due to the law of conservation of energy. During this process, the internal energy of low temperature would be converted into internal energy of high temperature.

On the page http://www.lpg.musin.de/physik/geheimnis-zeit/geheimnis_zeit.html of the Luitpold-Gymnasium in Munich, students under the direction of Mr. J. Hoffmüller have small, very smart video films on the subject of "Reversible and irreversible processes "created. On this page you will also find instructions on how you can create such films yourself

From the animations, films and your own experience you can see:

• There are reversible Operations. A film of the process can run forwards and backwards and both seem to us to be possible. Approximately reversible processes are only possible in nature if friction can be largely eliminated.

• The vast majority of processes in nature take place in a Direction. They are said to be irreversible.