The body weight in air is 80 N, and in water – 60 N. Find the force of Archimedes and the volume

The body weight in air is 80 N, and in water – 60 N. Find the force of Archimedes and the volume of the body completely immersed in water.

P1 = 80 N.
P2 = 60 N.
ρ = 1000 kg / m ^ 3.
Farkh -?
V -?
Only the gravity force m * g and the suspension reaction N1 act on the body in the air. N1 = m * g.
For 3 Newton’s law, the weight of the body is P1 = N1, P1 = m * g.
The body in water is affected by the force of gravity m * g and the reaction of the suspension N2 and the force of Archimedes Farkh.
N2 = m * g – Farch.
For 3 Newton’s law, the weight of the body is P2 = N2, P2 = m * g – Farch.
P2 = P1 – Farch.
Farch = P1 – P2.
Farch = 80 N – 60 N = 20 N.
Farch = ρ * g * V.
V = Farch / ρ * g.
V = (P1 – P2) / ρ * g.
V = (80 N – 60 N) / 1000 kg / m ^ 3 * 9.8 m / s ^ 2 = 0.002 m ^ 3.
Answer: Farch = 20 N, V = 0.002 m ^ 3.