Question

A ladder of length l carrying a man of mass m at its end is attached to the basket of a balloon of mass M. The entire system is in equilibrium in the air. As the man climbs up the ladder into the balloon, the balloon descends by a height h.
The potential energy of the balloon

• A. Decreases by mgh
• B. Increases by mgh
• C. Increases by mg (l - h)
• D. Increases by mgl

Answer 1

Answer: (B)

Increases by mgh

Work done by man $=mgl$

as balloon descends,

$\Rightarrow mgl=mgl-mgh+E$

$\Rightarrow E=mgh$

The potential energy of balloon measured by $mgh.$

Hence, the answer is increases by $mgh.$