Question

What is the frequency of a photon whose wavelength is `6.8xx10^-7*m`?

Answer 1

We use the relationship `lambdaxxnu=c`, where `lambda-="wavelength (m)"`, and `nu="frequency"` `(s^-1)`

Explanation:

And clearly their product, `lambdaxxnu` gives units of `m*s^-1` as is absolutely required for a velocity.

So we wants `nu=c/lambda=(3xx10^8*m*s^-1)/(6.8xx10^-7*m)`

`=4.41xx10^(+14)*s^-1` or `4.41xx10^14*Hz`