Question

Super Invar, an alloy of iron and nickel, is a strong material with a very low coefficient of thermal expansion (0.20× 10−6 C∘). A 1.9-m-long tabletop made of this alloy is used for sensitive laser measurements where extremely high tolerances are required.Part AHow much will this alloy table expand along its length if the temperature increases 5.5 C∘?Express your answer to two significant figures and include the appropriate units.Part BHow much will a 1.8-m-long table made of steel expand along its length if the temperature increases5.5 C∘?Express your answer to two significant figures and include the appropriate units.

Answer 1

Answer:

a) 2.1 × 10^-6 m b) 1.3 × 10^-4 m

Explanation:

The thermal expansion of super Invar 0.20 ×10^-6oC^-1 and the length of Super is 1.9 m

using the linear expansivity  formula

ΔL = αLoΔt where ΔL is the change in length meters, α is the linear expansivity of Super Invar in oC^-1 and Δt  is the change in temperature in oC. Substituting the value into the formula gives

ΔL = 0.2 × 10 ^-6 × 1.9 m ×5.5 = 2.1 × 10^-6 meters to two significant figure

b) the thermal expansion of steel is 1.3 × 10^-5 oC^-1 and the length of steel is 1.8 m

using the formula

ΔL of steel = 1.3 × 10^-5 × 1.8 ×  5.5 = 1.3 × 10^-4 m to two significant figure.