Question

A balloon filled with air is just floating in water in a beaker, as shown in fig. If the balloon is submerged more by a small distance and released, then the balloon will move up or move down to bottom or remains at the same location where released. Explain.

Answer 1

When the balloon is submerged more by a small distance, the pressure on the air in the balloon will increase, consequently the volume of the balloon will decrease, which inturn will decrease the buoyant force on balloon. Now the downward force (= weigth of air in balloon + downward thurst dueto liquid column) becomes more than the buoyant force on balloon. As a result of it, the balloon sink to the balloon sinks to the botton.