Answer
See solution for explanation.
Work Step by Step
a) The buoyancy force is equal to the weight of the displaced fluid, so the center of buoyancy acts at the center of the submerged part of the object.
b) Stable equilibrium occurs when the object returns to its original position after it has been displaced. For this to happen, the center of buoyancy, which acts upward, must be above the center of gravity, which acts downward. Otherwise, the submerged object will flip.
