http://schoolsolver.com/questions/18-At-20°C-a-rod-is-exactly-20.05-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-20.11-cm-on-the-same-ruler-What-is-the-coefficient-of-linear-expansion-for-the-material-of-which-the-rod-is-made/