Minimum Velocity of Nuclei in Nuclear Fusion

[akmphy]

? Nuclear Fusion

Homework Statement

Two deuterium nuclei overcome the Coulomb
force of repulsion and attain the necessary
1 × 10−14 m distance for fusion.
What is the minimum initial velocity of
each nuclei, as measured in the center-of-
mass frame? The permittivity of free space
is 8.85419 × 10−12 C2/N · m2, the mass of a
proton is 1.67262 × 10−27 kg, the mass of a
neutron 1.67493 × 10−27 kg and the charge
on an electron −1.60218 × 10−19 C.
Answer in units of m/s.

Homework Equations

I do not know how to do this:
2mv.5(v)=ka/rm
r=separation b/w nuclei

The Attempt at a Solution

I am more than willing to work this out with someone. Usually I have an attempt; however, I believe I have no where to begin. Any help is appreciated.

 

[zhermes]

Think of it in terms of a classical collision problem. E.q. a car crashes into a spring (or something like that). What determines how close the particles get?
What is conserved throughout the process?