Question

A stone thrown on glass window, smashes the window pane to pieces, but a bullet from the gun passes through making a clear hole why?

Answer 1

The velocity of stone is much less than that of the bullet fired from a gun. Due to its low speed the stone remains in contact with the window pane for a longer time and hence motion is shared by whole of the window pane.

On the other hand, the bullet fired from gun, remains in contact with the window pane for such a small time that it shares its motion only with a portion of the window pane. That's why it makes a clean hole in the window pane.