second and first moments $\overline M \equiv
M_2/M_1$. In order to demonstrate the effect of rescaling the impact velocity, in the main panel of Fig.\[avgfra\] the average fragment mass $\overline M$ is presented as a function of the impact velocity $v_0$ for the system size $R=30$cm obtained at different impact angles $\theta$, and in the inset the same curves are shown as a function of the normal component of $v_0$. It can be seen that for each impact angle $\overline{M}$ has a peak which broadens and gets shifted towards larger velocity values with decreasing impact angle. However, when plotting the same quantity as a function of the normal components of the impact velocity $v_0\sin{\theta}$ all the curves fall on top of each other. Larger fluctuations arise below the critical point which are more dominant for lower impact angles. Note that the position of the maximum in the inset coincides with the transition point determined in Fig. \[maxmas\].

![\[specific\] Average fragment mass $\overline M$ as a function of specific energy $E_0/m_{tot}$. The critical point, [ *i.e.*]{} the position of the maximum, depends on system size. ](figures/speng_avgmas_90_all.eps){width="50.00000%"}

Studies of fragmentation of various types of brittle solids have revealed that a larger amount 