Buoyancy situation of fluid statics such that Archimedes principle is applicable, and is thus the sum of the buoyancy force and the object's weight If the buoyancy of an (unrestrained and unpowered) object exceeds its weight, it tends to rise. An object whose weight exceeds its buoyancy tends to sink. Calculation of the upwards force on a submerged object during its accelerating period cannot be done by the Archimedes principle alone; it is necessary to consider dynamics of an object involving buoyancy. Once it fully sinks to the floor of the fluid or rises to the surface and settles, Archimedes principle
Neutral buoyancy suited astronaut trainees interact with mock-up space hardware, with the assistance of scuba divers. At the University of Maryland's Space Systems Laboratory, a neutral buoyancy tank is similarly used to evaluate the performance of prototype space robots. When neutral buoyancy is taking place, it appears as though the object/substance is floating in the middle of the fluid, or somewhere in between the bottom and the surface. A fish's swim bladder controls buoyancy by adjusting the amount of gas in the swim bladder, allowing it to achieve neutral buoyancy at different depths. When a fish's overall density becomes higher or lower