Question

a stone thrown on a plass window smashes the window pane to pieces but a bullet from the gun passes through it making a clean hole. why?

Answer 1

The velocity of the stone is much less than that of the bullet from the gun. Due to its low speed, the stone remains in contact with the window pane for a longer time and its momentum is shared by the entire window pane. As a result it smashes into pieces. On the other hand, the bullet fired from the gun remains in contact with the window pane for short duration. So, the bullet can share the momentum only with the portion of the window pane it comes in contact with. As such it makes a clean hole in the window pane.