Answer:
1.53
Step-by-step explanation:
α=Δl/(l Δt) here α is coefficient of linear expansion Δl is change in length l is original length andΔt is change in temperature
Δl=0.00174m , l=3.50m ,Δt=21-(-11-5)= 21+11.5 =32.5 ⁰C
α = 0.00174 / (3.50×32.5)
= 1.53×10^-5 ( ⁰C)^-1