Question

A ruler is accurate when the temperature is 25°C. When the temperature drops to -16°C, the ruler shrinks and no longer measures distances accurately. However, the ruler can be made to read correctly if a force of magnitude 1.2 103 N is applied to each end so as to stretch it back to its original length. The ruler has a cross-sectional area of 1.50 10-5 m2, and it is made from a material whose coefficient of linear expansion is 2.10 10-5 (C°)-1. What is Young's modulus for the material from which the ruler is made?