Question

The brightest light detected from the star antares has a wavelength of about 103 nm. what is the frequency of this light?

Answer 1

The relationship between frequency f, speed of light c and wavelength
`\lambda` is

`c= \lambda f`

In our problem, the wavelength is
`\lambda=103 nm = 103 \cdot 10^(-9) m` while the speed of light is
`c=3 \cdot 10^8 m/s`, so the frequency of the light is

`f= (c)/(\lambda)= (3 \cdot 10^8 m/s)/(103 \cdot 10^(-9) m)=2.9 \cdot 10^(15)Hz`