How would I work this problem?

I don't fully understand how it's possible to work this problem with so little information. I would like some steps to solving this. Thanks in advance.





In a television picture tube, electrons strike the screen after being accelerated from rest through a potential difference of 27 000 V. The speeds of the electrons are quite large, and for accurate calculations of the speeds, the effects of special relativity must be taken into account. Ignoring such effects, find the electron speed just before the electron strikes the screen.How would I work this problem?
Use energy conservation. The electron has 27000 electron volts of energy =1/2mv^2


http://en.wikipedia.org/wiki/Electron_vo鈥?/a>How would I work this problem?
Remember F=m*a


a=F/m, you know mass of electron





so now you need F =?





F = fe = force in Newtons on an electron with charge e; where f is the flux density and e the charge of an electron.





and so on....