Question

An object is lifted from ceiling of a lift by means of a string. When the lift starts moving in the upward direction the string breaks and the object falls into the lift. Explain giving reasons.

Answer 1

Let the lift move upwards with acceleration a.

F.B.D of Block

Initially when lift was at rest $T=Mg$

Now, $T=Mg+Ma$

The string broke because force increases in the string which may be move than strength of the string material.