A piece of iron weighs 1 N. in water, determine its volume, the density of iron is 7.8 g / cm3.

Initial data: P (weight of a piece of iron in water) = 1 N.

Reference data: ρzh (iron density) = 7800 kg / m ^ 3; ρw (water density) = 1000 kg / m ^ 3; g (acceleration due to gravity) = 10 m / s ^ 2.

The density of iron is greater than the density of water and the piece of iron will be completely submerged in water.

Equilibrium equation:

P = m * g – ρw * g * V = ρw * V * g – ρw * g * V = V * (ρw * g – ρw * g).

V = P / (ρl * g – ρw * g).

V = 1 / (7800 * 10 – 1000 * 10) = 1.47 * 10 ^ -5 m ^ 3 = 14.7 cm ^ 3.

Answer: The volume of a piece of iron is 14.7 cm ^ 3.