If it takes 3250 MeV of work to accelerate a proton from rest to a speed of v, determine v

You must determine the relativistic kinetic energy of the particle and solve for velocity. If the speed isn't close to the speed of light, you can approximate it with

E \approx \frac 12 mv^2

but you probably already know that. The relativistic formula is

E = mc^2 \Large (\frac {1}{\sqrt{1-(v/c)^2}} - 1)

Here's a link that will give you more information.

Kinetic energy - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Kinetic_energy)