Question

The least buoyant force on a rock is when it is submerged. A) near the surface. B) halfway to the bottom. C) near the bottom. D) none of the above

Answer 1

The least buoyant force on a rock is when it is submerged near the surface (A). Therefore, the correct option is A.

Step-by-step explanation:

The buoyant force experienced by an object submerged in a fluid is equal to the weight of the fluid displaced by the object. This force is given by Archimedes' principle, and it depends on the density of the fluid, the volume of the displaced fluid, and the acceleration due to gravity.

When a rock is submerged near the surface, the volume of fluid displaced is relatively smaller compared to when it is submerged deeper. As the rock goes deeper, the volume of fluid it displaces increases, leading to a larger buoyant force. However, the weight of the rock remains constant, resulting in a net decrease in the effective buoyant force acting on the rock.

Therefore, the least buoyant force is experienced when the rock is submerged near the surface. This is because the buoyant force is influenced by the volume of the displaced fluid, which is minimized near the surface, making option (A) the correct answer. Understanding the principles of buoyancy and fluid displacement helps in determining how the buoyant force changes with the depth of submersion.

Therefore, the correct option is A.

Answer 2

The least buoyant force is experienced by a submerged rock when it is near the surface of the fluid, due to the smallest pressure difference between the top and bottom of the rock at this depth.The correct option is a.

Step-by-step explanation:

The student is asking about the conditions under which the least buoyant force acts on a rock when submerged in a fluid. The buoyant force is always present whether an object floats, sinks, or is suspended in a fluid. This force results from the pressure difference between the bottom and the top of the object and because pressure increases with depth, the force is dependent on the object’s depth in the fluid.

The least buoyant force on a submerged rock is near the surface of the fluid. This is because the pressure difference between the top and bottom of the rock is lowest near the surface, leading to a smaller buoyant force. As the rock is submerged deeper, the pressure at the bottom increases, resulting in a greater buoyant force. Therefore, the correct answer to the student's question is A) near the surface.