Steel and aluminum rods have a mass of 2 kg and a cross-sectional area of 4 cm2.

Steel and aluminum rods have a mass of 2 kg and a cross-sectional area of 4 cm2. which of the rods is longer and by how much?

Given:

m1 = m2 = 2 kilograms is the mass of steel and aluminum rods;

S1 = S2 = 4 cm ^ 2 = 0.0004 m ^ 2 – the cross-sectional area of the rods;

ro1 = 7700 kg / m ^ 2 – steel density;

ro2 = 2700 kg / m ^ 2 is the density of aluminum.

It is required to determine the difference in the lengths of the rods h2 – h1.

Find the length of the steel bar:

h1 = V1 / S1 = m1 / (ro1 * S1) = 2 / (7700 * 0.0004) = 2 / 3.08 = 0.65 meters.

Find the length of the aluminum rod:

h2 = V2 / S2 = m2 / (ro2 * S2) = 2 / (2700 * 0.0004) = 2 / 1.08 = 1.85 meters.

h2 – h1 = 1.85 – 0.65 = 1.2 meters.

Answer: The aluminum rod is 1.2 meters longer.