Put and describe experiments on changing the internal energy of the body through the performance of work and through heat transfer.

Available experiences – change temperature or state of aggregation.
We take plasticine. We put it under a table lamp (incandescent lamp). After a while, it will heat up. Now we take the same piece and wrinkle it with our hands. We demonstrate that both heating and work on the body lead to the same result – heating.
We take a nail, a hammer and a portable anvil, hitting the nail with a hammer several times, we observe that it gets very hot.
We take a pump for a bicycle and intensively do 20-30 “strokes”. The pump will heat up – because each time the gas is compressed in the pump, work is done and the gas heats up.
Another spectacular experience. When liquid evaporates from the surface, the body cools. Take the long-necked flask on the sphere.
Wrap gauze or any cotton fabric on the spherical part. Get it wet. Turn the flask upside down and dip the neck into the water. The water evaporates from the fabric. The flask is cooled. The pressure in her drops. Water is sucked into the flask. In addition, the pressure drop, and therefore the temperature change, can be calculated from the height of the liquid column.

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