= 45^{\circ}$. ](crack/crack_75_518.ps "fig:"){width="40.00000%"}
                                                                                                                                                                                  (a)                                                                                                                                                                                                                                                                                                                                                                 (b)
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   ![\[snap2\] The reassembled snapshots of normal and oblique impacts at different velocities keeping the normal component constant as $500$cm/sec. The crack patterns are almost same in all cases. (a) $\theta = 90^{\circ}$. (b) $\theta = 75^{\circ}$. (c) $\theta = 60^{\circ}$. (d) $\theta = 45^{\circ}$. ](crack/crack_60_578.ps "fig:"){width="40.00000%"}   ![\[snap2\] The reassembled snapshots of normal and oblique impacts at different velocities keeping the normal component constant as $500$cm/sec. The crack patterns are almost same in all cases. (a) $\theta = 90^{\circ}$. (b) $\theta = 75^{\circ}$. (c) $\theta = 60^{\circ}$. (d) $\theta = 45^{\circ}$. ](crack/crack_45_708.ps "fig:"){width="40.00000%"}
                                                                                                                                                                                  (c)                                                                                                                                                                                                                                                                                                                                                                 (d)
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Results
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Studying the evolution of the final crack patterns when changing the impact velocity, we have identified a critical velocity $v_c$ which separates the regimes of different break-up mechanisms. In the following, we analyze characteristic quantities of the break-up process, and show that there are substantial differences between the two regimes.

Size Distribution of Fragments {#size}
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![\[maxmas\] The mass of the first and second largest fragment as a function of the normal component of the impact velocity $v_0\sin{\theta}$ at different impact angles $\theta$ and velocities $v_0$ for a system size $30$ cm. 