Time evolution of the relative velocity profiles (top) and the ratio profiles (bottom) for targets and projectiles of radii 100 km. The profiles represent the case for km and a disk six times more massive than the MMSN. Despite the higher values of the relative velocities of planetesimals with r_p = 100 km, the ratio is lower compared with the case for small planetesimals. This is because the specific impact energy () for planetesimals of r_p = 100 km is approximately three orders of magnitude higher than that for planetesimals of r_p = 0.1 km. (Color version online.)