Stability of Immersed Bodies
For an immersed body to be stable, the buoyant force must be less than or equal to the weight of the object, as shown below. If the buoyant force is stronger, the body is unstable.
Real Life Example of Immersed Bodies:
Submarines increase their weight to sink and decrease it to surface. This is done by storing or emptying their ballast tanks with water. A submarine with full ballast tanks will sink because its weight is greater than the buoyant force. If the submarine’s ballast tanks are empty, it will surface because the buoyant force is greater than its weight. In this case, the stability depends on where the centre of gravity is on the submarine.
