Challenging JEE advanced Physics .

At a point $A$ of a drum, a rope (length $l_0 > h$ , total mass $m_0$ ) is attached, the lower part of which initially rests on ground $C$ . At time $t = 0$ the drum starts to rotate such that the rope is lifted with constant acceleration $a_0$ and reeled. For $t = 0$ point $A$ is at $s = 0$ .

Determine the force in the rope at the drum inlet $B$ when one part of the rope still rests at the ground. Assume that the rope hangs vertical at all the times.

Given : $m_0 = 5$ $kg$ , $l_0 = 10 m$ , $h = 1 m$ , $a_0 = 5 m/{s^2}$ , $g = 10 m/{s^2}$ , $s = 1 m$ .