Question

An object is placed in a fluid and then released. Assume that the object either floats to the surface (settling so that the object is partly above and partly below the fluid surface) or sinks to the bottom. (Note that, for Parts A through D, you should assume that the object has settled in equilibrium.)
A.Consider the following statement: The magnitude of the buoyancy force is equal to the weight of fluid displaced by the object.
Under what circumstances is this statement true?

A. always
B. only for an object that floats
C. only for an object that sinks
D. never

Answer 1

Answer:

A. Always true

Explanation:

This is because, the buoyancy force is always present whenever and object is placed in a fluid. The magnitude of this  buoyancy force is always equal to the weight of the fluid    displaced by the object according to Archimedes' principle. This principle is true irrespective of whether the object floats or not. When any object is inserted in a fluid, the buoyancy force is always present irrespective of whether it floats or not.  

Answer 2

Answer:

The correct option is;

A. always

Explanation:

Archimedes' principle states that when an object is immersed in a fluid, and it is either partially or wholly submerged, the upward force acting on the object, that is the buoyancy force, is equal to the weight of the fluid displaced by the object.

That is the object immersed in the fluid is observed to have an apparent reduction in weight that is equal to the weight of the volume of the fluid displaced by the  immersed  object.

Therefore, the above principle always occurs.