Question

How can I calculate the wavelength in meters?

Answer 1

The SI unit of the system defines several units as standard as to be used in calculations. But the system of measurements is not just made up of one unit that is used. There are several other units that are used and they can be equally converted from one unit to another based on our need. Not all the units are used for the use.

Complete step by step answer:
Usually, the wavelength is calculated in meters as the meter is the SI unit of the distance covered.
For the visible range if the light wavelength is between 350 to 750 nanometre where 1 nanometre is equal to $1 \times {10^{ - 9}}m$. The frequency of the light may be obtained from the relation as
$\nu = \dfrac{{{c_{speed\,\,oflight}}}}{{{\lambda _{wavelength}}}}$
The SI system of units describes the unit of length as meters. It is defined as the length of the path travelled by light in a vacuum in a time of 1 second. It is represented by ‘m’. Though the meter is the SI standard for the calculation of the distance, it is not the only unit that is used in daily practice.
Apart from the unit of meter, the other units are millimetre, centimetre, decimetre, decametre, hectometre and kilometre. All these units differ with each other in the multiple of 10.

Note: Just as the metre, there are SI units defined for most of the major measurements like the distance, time, luminous intensity, weight etc. All the units are set as the standards and the definitions of these measurements are clearly defined by the organisations.
There are many units that are more prevalent in some domains while others are obsolete in others.