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?

Question

asked Oct 9, 2019 106k views

1 Answer

Ventu · Answer 1 · 2019-10-13T16:45:49+0000

1) Frequency:
$7.06\cdot 10^(14) Hz$

The frequency of electromagnetic radiation is given by:

$f=(c)/(\lambda)$

where

$c = 3 \cdot 10^8 m/s$ is the speed of light

$\lambda$ is the wavelength

In this case, the wavelength of the radiation is

$\lambda=425 nm=425\cdot 10^(-9) m$

Therefore the frequency is

$f=(3\cdot 10^8 m/s)/(425 \cdot 10^(-9) m)=7.06\cdot 10^(14) Hz$

2) Period:
$1.42\cdot 10^(-15) s$

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

T=(1)/(f)

Using the frequency we found previously,
$f=7.06\cdot 10^(14) Hz$ , we find:

$T=(1)/(7.06\cdot 10^(14) Hz)=1.42\cdot 10^(-15) s$