1. The problem statement, all variables and given/known data At 20°C, a rod is exactly 21.03 cm long on a steel ruler. Both the rod and the ruler are placed in an oven at 270°C, where the rod now measures 21.26 cm on the same ruler. What is the coefficient of thermal expansion for the material of which the rod is made? The linear expansion coefficient of steel is 11 x 10-6 /C°. 2. Relevant equations change in length = rod length * coefficient of linear expansion * change in temperature (C) 3. The attempt at a solution I can find out the thermal expansion of the rod, but how does the coefficient of steel go into that equation?! I cannot figure it out. Here is my attempt: 0.0023m = 0.2103 * coefficient of linear expansion * 250 Therefore, the coefficient of linear expansion is about 4.4e-5, but that answer is wrong. Please help! Thanks in advance to all help!