With what force is a piece of wood weighing 800 g pushed out when it is completely immersed in water? Birch tree

The buoyancy force of Archimedes will act on a piece of birch in water, which is equal to:
Fa = ρ * g * V, where ρ is the density of water (we take ρ = 1000 kg / m ^ 3), g is the acceleration of gravity (we take g = 9.8 m / s ^ 2), V is the volume of the submerged part of the piece birch (V = m / ρb; where m is the mass of a piece of birch, m = 800 g = 0.8 kg; ρb is the density of birch, we take ρb = 650 kg / m ^ 3).
Let’s calculate the buoyancy force of Archimedes:
Fa = ρ * g * V = ρ * g * m / ρb = 1000 * 9.8 * 0.8 / 650 ≈ 12.1 N
Answer: The buoyancy force of Archimedes is 12.1 N.