What is the Wavelength of the Ejected Electron?

[mirandab17]

Homework Statement

The threshold frequency of a metal is 3.184 x 10^14 Hz. If a photon of wavelength 368 nm strikes the surface of the metal, what is the wavelength of the ejected electron?

Homework Equations

f (frequency) = c/(wavelength)
Eincident = Ethreshold + KE
E=fv(wavelength)

The Attempt at a Solution

Oh man... here it is. I bet I'm missing something huge but it's just been killing me.

 

[TeethWhitener]

You're good up through the energy calculation. From there you can use:
$$KE = \frac{p^2}{2m}$$
to get a value for your momentum. Then just plug that number in to:
$$\lambda = \frac{h}{p}$$
and you get your answer.