If the coefficient for linear expansion of copper is approximately 16.8 x 10-6 degC-1, what percent increase would a copper rod 45.0 cm long have if it had a temperature change of 111 degC?

Answer 1

The increase in length of a metallic rod is proportional to the product of the original length and the temperature change. The final length is then equal to the original length and the increased length due to the temperature.

The increase in length is thus ΔL = 16.8 x 10^-6 /°C x 111 °C x 45.0 cm = 0.0839 cm. The percent increase is the increase divided by the initial length x 100. This is 0.0839 cm/45.0 cm x 100 = 0.186%.