A plastic block is held completely submerged and at rest in water and then released. The mass of the block is less than the mass of the water it displaces. Which statement best describes the block’s initial acceleration immediately after release?
(a) It accelerates upward with a magnitude equal to g because immersion makes the block effectively weightless.
(b) It accelerates upward with a magnitude greater than g because the buoyant force exceeds its weight.
(c) It accelerates upward with a magnitude less than g because the upward buoyant force is only partially opposed by its weight.
(d) It accelerates downward with a magnitude less than g because the upward buoyant force only partially cancels its weight.