Briefly

The globe in balance

The globe in balance

We have a balloon full of air submerged under water and tied to a weight that keeps it in an equilibrium position, so that neither rises nor falls. Now we sink ten centimeters more the globe pushing it towards the bottom.

What will happen to the globe: will it rise to its former equilibrium position, will it sink to the bottom or will remain in the depth in which we have left it?

Solution

The balloon will sink to the bottom since being lower it supports the pressure of a larger water column, so it will cease to be in balance and will slowly sink towards the bottom.