Question

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?

Answer 1

frequency = 7.058*10^14 Hz

time period = 1.41*10^-15 s

Step-by-step explanation:

by formula

f = c / λ

c is constant which is = 3 * 10^8

λ is given = 425 * 10^-9 m

f= 3* 10^8 / 425 * 10^-9

f = 7.058*10^14 Hz

T= 1/f

T = 1 / 705882.3529

T= 1.41*10^ -15 s

Answer 2

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

The frequency of a light wave is given by:

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

where

`c=3\cdot 10^(-8) m/s` is the speed of light

`\lambda` is the wavelength of the wave

In this problem, we have light with wavelength

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

Substituting into the equation, we find the frequency:

`f=(c)/(\lambda)=(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 of a wave is equal to the reciprocal of the frequency:

`T=(1)/(f)`

The frequency of this light wave is
`7.06\cdot 10^(14) Hz` (found in the previous exercise), so the period is:

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