An object floats in a liquid with half of its volume submerged in the liquid. What is the buoyant force acting on the object?

The correct answer is D, equal to its weight. A floating body is at rest, so the upward buoyant force must exactly balance the downward weight of the object. By Archimedes' principle the buoyant force equals the weight of the liquid displaced, so a floating object always displaces liquid weighing as much as the object itself. Here only half the volume is inside the liquid, which tells us that half the object's volume of that liquid weighs as much as the whole object, so the object's density is half the density of the liquid. How much of the body stays under the surface depends on this density ratio, not on the size of the buoyant force. A is wrong because a liquid always pushes up on a body dipped in it. B is wrong because a smaller upward force would let the object sink further. C is wrong because a larger upward force would push the object up until less of it stayed submerged. Exam tip: floating means buoyant force = weight; fraction submerged = density of body ÷ density of liquid.