please, can someone tell me how to calculation the force in submarine, buoyant force and archimedes's...?

Answer 1

The buoyant force is equal to the weight of the displaced fluid. Put a submarine in a large graduated container such as a canal lock, and see how high the water rises when it's submerged, you could ascertain the volume of the submarine.

Answer 2

The buoyant force is not equal to m*g of the object...buoyant force is equal to the weight of the fluid (in this case = water) displaced (which could be thought of as m*g of the water displaced). Rho * volume gives you a mass, and g is the acceleration due to earth's gravity, so it is the same as m*g of the water displaced. If the buoyant force is greater than the weight of the object, then it will float. If Fb is equal to the weight of the object, then it may be suspended somewhere in the water column. If the buoyant force is less than the weight of the object, then the object sinks. If an object is floating at the surface (partially submerged), then it isn't really displacing an amount of water equal to its total volume...rather, it is displacing an amount of water equal to the volume of the object below the surface (think iceberg). I hope this helps!