Question

A man of mass $m$ is suspended in air by holding the rope of a balloon of mass $M$. As the man climbs up the rope, the balloon :

• A. moves upward
• B. moves downward
• C. remains stationary
• D. cannot say anything

Answer 1

The correct option is B moves downward

Net external force on the system of (man+ balloon) is zero, and centre of mass of the system is initially at rest.

$\Rightarrow$So position of centre of mass will not change. Therefore to maintain $x_{\text{cm}}=\text{constant}$ the balloon will move downwards.