Question

why a neat hole is formed in the glass pane,if a bullet is fired on it from a close range?

Answer 1

When the bullet strikes the glass pane, the part of the glass pane which comes in contact with the bullet immediately shares the large velocity of bullet and makes a neat hole. The remaining part of the glass remains at rest as there is no time for the other parts to share the velocity and is therefore not cracked, due to inertia of rest.

Answer 2

When bullet strikes the glass pane, it suddenly sets only that part into motion. However, rest of the glass pane on account of inertia of rest tends to continue in its state of rest. Thus, a neat hole is made in the glass pane as the rest of pane does not get disturbed.