Top: planetesimal accretion rates for different planetesimal sizes, for a disk ten times more massive then the MMSN, in which p = 5/3 and km, as a function of time. The dashed black line represents the total planetesimal accretion rate for the case without planetesimal fragmentation (WF). The dashed red line represents the total planetesimal accretion rate for the case with planetesimal fragmentation in which p is calculated with Eq. (31), our basis model (BM). The solid red line represents the total planetesimal accretion rate for the case with planetesimal fragmentation with p = 5/3. Bottom: time evolution of the total planetesimal accretion rates (solid lines) and the accretion rates of fragments of 1 m (dashed lines) for the case where only planetesimal fragmentation is considered (red lines) and for the case in which planetesimal coagulation and fragmentation are considered (black lines). The plot corresponds to a disk ten times more massive then the MMSN and for the case of km. (Color version online.)