The wavelength of violet light is about 425 nm (1 nanometer = 1 × 10−9 m). what are the frequency and period of the light waves?

1. Frequency:

The frequency of a light wave is given by:

where

is the speed of light

is the wavelength of the wave

In this problem, we have light with wavelength

Substituting into the equation, we find the frequency:

2. Period:

The period of a wave is equal to the reciprocal of the frequency:

The frequency of this light wave is (found in the previous exercise), so the period is: