1. The problem statement, all variables and given/known data 1. A uniform electric field is directed towards the east with a magnitude of 10 N/C. A proton, moving with a speed of 10^5 m /s, enters the field traveling parallel to it. The proton covers a distance of 4 cm while in the field. Find the proton’s final velocity as it leaves the field. 2. Relevant equations F=(k)(q1)(q2)/r, F=mv^2/r, Ac=v^2/r 3. The attempt at a solution I don't understand how to attempt this problem. Confused about the 4cm, not sure if where to use it. How does the proton's velocity change when it enters an electric field?