Energy absorption by substance causes or its transformation into heat, or transformation to other form. In the second case some part of energy will also be transformed to heat as the efficiency of any physical system cannot exceed unit.
Instruction
1. Absorption of light energy requires the substance which is opaque and nonreflecting for radiation with the chosen wavelength. For example, blue light is absorbed by red objects and vice versa. Black objects absorb light beams of all visible range. Consider, however, that the subject seeming dark to a human eye can be light for invisible beams (infrared, ultra-violet) and vice versa. So, it is established that human skin of any color seems in infrared light white, and the usual windowpane badly passes short-wave ultraviolet rays. That light radiation which was not reflected from an object and did not pass through it will be absorbed by it and will turn into heat.
2. Some physical devices allow to accumulate light energy or to transform it to other types of energy. So, for example, if to focus beams of the sun on the Stirlinga engine cylinder painted in black color, it will heat up and will start moving. Direct light to a zinc sulfide layer, and then stop lighting - and within several minutes this layer will radiate a small part of the absorbed energy back in the form of light. The solar battery, absorbing light energy, turns it into electric. Efficiency of all these converters seldom exceeds 10 percent.
3. It is possible to absorb not only light, but also thermal energy. To save up a large amount of heat in small volume, take a metal cylinder, fill it with paraffin and seal. If to heat such thermal accumulator, it then can use as a hot-water bottle for a long time. Thermohair curlers work at this principle. To transform a part of the absorbed thermal energy to electric, use the thermocouple. At last, heat engines of the most various designs allow to carry out partial transformation of a part of the absorbed thermal energy into electric.
4. The accumulator is the device which absorbs electric energy and a part it turns into heat, and other part - into internal (chemical) energy which keeps in itself. Connect to it loading, and it will give it this energy. It is possible to load and discharge the accumulator repeatedly. Electric motors at absorption of electric energy turn some of its part into mechanical, and electric light sources - in radiant.
5. For absorption of the kinetic energy presented in the form of vibrations, and its transformations in thermal serve shock-absorbers. There are shock-absorbers combined with electric power generators. Unlike classical generators, they do not contain the rotating parts - all their details move returnable progressively. In such devices some part of the absorbed energy of vibrations turns into the electric power However, ordinary electric generators carry out a similar task - only the way of transfer of kinetic energy to them for absorption differs. All microphones absorb energy of acoustic waves, but only some of them will transform a part it to electric - dynamic, tape, piezoceramic. Other microphones - coal, electret with the built-in amplifier - all absorbed acoustic energy turn into thermal completely. They only operate under the influence of the accepted fluctuations more powerful stream of the electric energy given from the outside.