Question

How do you calculate the frequency of light if the given wavelength of light is `400nm`? The speed of light is `c= 3 xx 10^8 m/s`?

Answer 1

I found: `7.5xx10^14Hz`

Explanation:

The wavelength `lambda` and frequency `nu` are related through the speed of light in vacuum `c` as:
`c=lambda*nu`
So using your data we get:
`nu=c/lambda=(3xx10^8)/(400xx10^-9)=7.5xx10^14Hz`