A metal rod is 40.125 cm long at 20 °C and 40.148 cm long at 35 °C. calculate the coefficient of linear expansion of the rod for this temperature range.

Answer 1

a = (L'-L)/(L*deltaT)
= (0.023/40.125)[1/(35-20)]
= 3.82*10^-5 (degC)^-1

Answer 2

change in length/length = k * change in T

k = (40.148-40.125)/(35-20) / 40.125