Question

What is the frequency of a green light, which has a wavelength of `4.90 * 10^-7`m?

Answer 1

I found: `nu=6xx10^14 Hz`

Explanation:

You can consider that wavelength `lambda` and frequency `nu` are related through the speed of light in vacuum `c` as:

`color(red)(c=lambda*nu)`

so:
`3xx10^8=4.9xx10^-7*nu`
and:
`nu=(3xx10^8)/(4.9xx10^-7)=6xx10^14 Hz`