The Fracture motion rollout has parameters to control how outward velocity is applied to fracture particles.
Particles move outwards: controls whether outward forces will be applied to fracture particles.
Multiplier: the strength of the fracture force to apply to new particles, in the direction of the original particle’s position to the new particle’s position (normalized to the maximum length from fracture-to-source for all fracture particles).
Inherit %: the amount of velocity to inherit from the original particle.
Divergence: the degrees of divergence to apply to fracture forces.