Multiple-Concept Example 4 reviews the concepts that are involved in this problem. A ruler is accurate when the temperature is 25 °C. When the temperature drops to −14 °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 1.6 × 10⁻⁵ m², and it is made from a material whose coefficient of linear expansion is 2.5 × 10⁻⁵ (C°)⁻¹. What is Young’s modulus for the material from which the ruler is made?