I have been very confused about this for some time now. We know that when an elevator accelerates upward, the apparent weight of a body placed inside it equals the normal force exerted by the elevator and this force acts in the upward direction. But why doesn't this logic hold for the buoyant forces in fluids, even though they are the normal forces present in fluids and act in the upward direction? For example, suppose a person is submerged in a swimming pool, then the water will exert a buoyant force on the person and that force will be equal to the weight of the displaced water. But why does this force, reduce the apparent weight of the body, unlike the force in the elevator? Because apparent weight of a body is - by definition - equal to the normal force on the body and I've read that in the case of fluids this normal force is the buoyant force, so why isn't the apparent weight equal to the buoyant force? For example, if a body weighs 10 N and it is completely submerged in water such that the buoyant force(which is the Normal Force here) = 8 N, so shouldn't the apparent weight = 8 N also? Are some other forces, which are unknown to me, playing a role here? ( Interestingly, in a similar question asked here, an answer said that the apparent weight of a completely submerged body Is equal to the buoyant force; while another source said that the apparent weight will be equal to the difference between the true weight and buoyant force. So, which one is right?). Also, what would happen if an object is placed on a weighing machine that is atop water shooting out of a fountain (and accelerating)? I think because it's analogous to the elevator case the weighing machine would register an increased mass (i.e. the apparent weight would be greater), am I correct?
Bonus question: I read that once a body gets completely submerged under a fluid, the buoyant force experienced by it doesn't change. Then, why does it get increasingly hard for us to push the object farther down to the bottom?