A little girl is holding a helium-filled balloon on a string while riding in a closed elevator going down a very tall building at constant speed. There is vacuum in elevator. Suddenly the elevator cab

Question

A little girl is holding a helium-filled balloon on a string while riding in a closed elevator going down a very tall building at constant speed. There is vacuum in elevator. Suddenly the elevator cable snaps, sending the elevator into free fall. Being shocked, the girl lets go of the string. She is even more surprised to see

TestHub · Accepted Answer

The elevator is in free fall in vacuum, so everything inside falls with the same acceleration $g$ and there is no buoyancy (no air).

The balloon has zero net force in the elevator frame, so it stays where the girl let it go: it remains stationary relative to the elevator.

Physics - NLM Question with Solution | TestHub

Options:

Doubts & Discussion