At 11°C, an aluminium rod is 10cm long and a steel rod is 80cm.Both have same diameter. The temp. is raised to 80°. What is the increase in length of the joined rod in mm?

Question

The coefficient of linear expansion of aluminium and steel is 2.4*10^-5 and 1.2*10^-5 respectively.

Answer 1

ΔL/L₀ = α(T-T₀) where ΔL is the change in length and α is the linear coefficient of thermal expansion. Plug into the equation ΔL = αL₀ΔT for each material. You need to look up the coefficients. The length units will come from the L₀