Question

A clean hole is made in a glass window pane when it is struck by a bullet fired from a gun. Whereas, the same window pane will be broken to pieces when struck by a stone of similar size. Explain the phenomenon quoting the relevent priciples.

Answer 1

Explanation:

1. Bullet fired from a gun will have greater velocity and the velocity of stone will be much less than that of the bullet.
2. Hence, the bullet will have more momentum.
3. Due to the low speed of the stone, it will remain in contact with the window pane more than that of the bullet fired from the gun.
4. Thus, the motion of stone is shared with the whole window pane and broken it into pieces.
5. While the bullet remains in contact with the window pane for a very short time due to the speed of the bullet.
6. Thus, the bullet shares the motion to a very small area.
7. Hence, a clean hole is made in the window pane when it is struck.