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



but you probably already know that. The relativistic formula is



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

Kinetic energy - Wikipedia, the free encyclopedia