Explain why objects experience a buoyant force when immersed in a fluid. How can you find the value of the buoyant force?

Answer 1

There is a buoyant force because the pressure of the fluid and and near the bottom is higher than the pressure at higher points on the body. (Pressure increases linearly with depth).

You can compute the buoyant force easily using Archimedes principle, or measure it directly. You would need to measure the body's weight and the force needed to keep it fully submerged but not resting on the bottom.

If a body is floating on top of a fluid, the buoyant foce equals the weight.