For the Dohnanyi collisional cascade exponent and ,
Substitution in part (iv) yields
Thus
The dependence is the pair-collision scaling. Longer-lived clumps are more numerous, stronger bodies disrupt less often, and smaller fragments put more geometric cross-section into each event. At fixed total mass, increasing lowers the normalization of the power-law size distribution and therefore lowers the event rate.
A size-independent gives the steady Dohnanyi collisional cascade exponent . The preceding results become
Thus, under these idealized prescriptions, cratering collisions remove target mass about three times faster than catastrophic collisions. The conclusion concerns mass removed from targets; both processes contribute fragments to the collisional cascade.