Max Force on Protons at 1000km/s

[inferno_gogo]

Homework Statement

The problem states that two protons are aimed at each other with a certain velocity v. It asks what is the maximum electrical force they will exert on each other.
The velocity is given at 1000km/s. And that is everything given.

Homework Equations

KE = 1/2mv^2
F = q*q/(4*pi*e*r^2)

The Attempt at a Solution

I am stuck on the approach. I have managed to find the kinetic energy of the protons but that is it. I don't know where to go from here . I think I should use Coulomb's Law, but I need to find the radius for that. Any suggestions?

 

[Doc Al]

Hint: What can you say about the KE of the protons when they reach the minimum separation distance?

 

[inferno_gogo]

Great Help! Thank you very much, problem Solved.

 

[Redbelly98]

Just on a hunch, I'll ask if the total kinetic energy of the two protons was included in the problem solution.