Two spheres are brought into contact:

Sphere one:
r= 17.5 cm = 0.175 m
m= 150 g = 0.150 kg
q = -11.0 microcoloumbs = -1.1 * 10^-5 Coloumbs

Sphere two:
r= 30.5 cm = 0.305 m
m= 46.0 g = 0.046 kg
q= -28.0 microcoloumbs = -2.8 * 10^-5 Coloumbs

(r = radius, m = mass, q = charge )

The two spheres are then released, what is the maximum acceleration and velocity achieved by both spheres?

I've calculated the maximum accelerations because I calculated the electrostatic force between them, and I know the acceleration will be greatest when they are first released since the force is proportional to 1/distance^2.

I am unsure how to find the maximum velocity achieved, since the acceleration won't be constant. Is integration needed for this part of the problem?