A 160 km long electric power line made out of copper is installed during the Spring months at an average temperature of 10.7 °C. What is the change in the length of the power line on a hot Summer day, when the temperature is 31.8 °C? The coefficient of linear expansion for copper is 1.62×10-5 1/C°. Use positive sign for an increase in length and negative for a decrease.
What is the change in the length of the cable on a -30.4 °C cold Winter day?