As, Buoyant force is the net upward force on any object in any fluid. If the buoyant force is greater than the object's weight, the object will rise to the surface and float. If the buoyant force is less than the object's weight, the object will sink.

B(buoyant force) = -$V\rho g$

We all know that $V$ is volume of displaced fluid by an object.

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$$Question$$

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Suppose we have solid wooden cylinder which has iron ball attached to it on the TOP and I place this thing (wooden solid cylinder +small Iron ball system) inside water and we $observe$ that it is half submerged. So what is the buoyant force on the system by water.

**A) Is it $ρALg/2$ where $ρ$ is density of water, $A$ is cross sectional area of solid cylinder, $L$ is the length of cylinder**

**B) or is it $ρVg/2$ where $V$ = Total volume of SOLID CYLINDER + SMALL COPPER BALL which isn't equal to $ρALg/2$ because total volume of the system is AL + V′ where V′ is volume of small copper ball**