Question

Which of the following experiences a buoyant force?

• A. A man standing on a sand
• B. A solid cube which sinks in the water.
• C. Throwing a cork in the air
• D. Pushing an empty can into water.

Answer 1

The correct option is D

Pushing an empty can into water.

When you try to push an empty can in the water, the upward thrust on the can is more than the weight of the empty can. This results in less apparent weight. Because of this even if we apply greater force to the can in the water, it pushes the can in upward direction. The upthrust concept is meant for fluids, so the first choice is not a part of the concept. For throwing an object in air is not an example of buoyancy. And the object which sinks in the water, its weight is more than that of buoyant force, so no upward force for the solid cube which will push it up.