Do not know where to begin

gmuniz
Q An infinitely long line of charge has a linear charge density of 6.50*10^-12 C/m. a proton is a distance of 17.5 cm from the line and moving directly toward the line with a speed of 2900 m/s. How close does the proton get to the line charge? I am lost and do not know how to approach the problem or set it up.

$$q (V_{f} - V_{i}) = \frac{1}{2} m_{p} v^2$$