## College Physics (4th Edition)

As the frequency $f$ increases, the maximum kinetic energy of the ejected photons also increases.
We can write an expression for the maximum kinetic energy: $K_{max} = hf - \phi$ We can see that as the frequency $f$ increases, the maximum kinetic energy of the ejected photons also increases. This is quite intuitive as higher frequency photons have more energy than lower frequency photons.