Historically it developed so that concerning radio waves specify frequency more often, and concerning light radiation - wavelength. However, as both types of radiation have the identical physical nature, if necessary transfer of one of these sizes to another is possible.
Instruction
1. In the beginning determine the wavelength of light radiation. Any equipment for this purpose it is not required - to learn this size, with a sufficient accuracy, it is possible approximately. Red light has wavelength from 650 to 690 nanometers, red-orange - about 620, orange - from 590 to 600, yellow - from 570 to 580, lime - about 550, emerald - from 500 to 520, blue - from 450 to 480, violet - from 420 to 390. However, if experience is carried out not houses, and in physical laboratory, it is possible to determine light wavelength more precisely by means of the special device - a spectrometer.
2. For convenience, transfer light wavelength to meters. One nanometer is 10^(-9) meter. Use scientific calculator as usual is not capable to work with numbers in such range.
3. Now you have enough information to calculate the frequency of light radiation in hertz. The second size which needs to be used in calculations is the speed of light. It makes 299792458 meters per second. Divide this size into wavelength - and frequency will turn out.
4. Now, for convenience, transfer the received frequency to terahertz. One terahertz is equal 10^12 to Hz. The result has to be in range from 400 to 800 terahertz. Consider that frequency is inversely proportional to wavelength therefore red light corresponds to the lower bound of this range, and violet - top.
5. The same way it is possible to determine frequency by wavelength and vice versa concerning other types of radiation. Radio waves have frequencies from hundreds of kilohertzes to dozens of gigahertzes, and length of waves - from several millimeters to hundreds of meters. If radiation is not electromagnetic (for example, it is about a sound, ultrasound), consider that it extends much more slowly, than light. Besides, acoustic speed in much bigger degree, than the speed of light, depends on Wednesday in which radiation extends.