Question

A rod is measured to be exactly 21.29 cm long using a steel ruler at a temperature of 20.6°C. Both the rod and the ruler are placed in an oven with a temperature of 354.0 °C where the rod now measures 21.43 cm using the same ruler. What is the coefficient of thermal expansion for the material of which the rod is made?

Answer 1

Coefficient of thermal expansion of the material of the rod =

Initial length of the rod = L₁ = 21.29 cm

Initial temperature of the rod = T₁ = 20.6 ^oC

Final length of the rod = L₂ = 21.43 cm

Final temperature of the rod = T₂ = 354 ^oC

L₂ = L₁ + L₁(T₂ - T₁)

21.43 = 21.29 + (21.29)(354 - 20.6)

= 1.972 x 10^-5  oC^-1

Coefficient of thermal expansion of the material of the rod = 1.972 x 10^-5  oC^-1