A metal part weighs 50 N in air, and when immersed in machine oil 44.2 N. What is the density of the part

A metal part weighs 50 N in air, and when immersed in machine oil 44.2 N. What is the density of the part (density of machine oil 900 kg / m3)

Given: P1 (weight of a metal part in air) = 50 N; P2 (part weight when immersed in machine oil) = 44.2 N.

Constants: g (acceleration due to gravity) = 9.81 m / s2; according to the condition ρm (density of engine oil) = 900 kg / m3.

1) Determine the volume of the metal part: Fa = P1 – P2 = ρm * g * V, whence V = (P1 – P2) / (ρm * g) = (50 – 44.2) / (9.81 * 900) = 6.57 * 10-4 m3.

2) Calculate the density of the part: P1 = m * g = ρ * V * g, whence ρ = P1 / (V * g) = 50 / (6.57 * 10-4 * 9.81) = 7759 kg / m3.