Chapter 12 Problem 020 MultipleConcept Example 4 reviews the

Chapter 12, Problem 020 Multiple-Concept Example 4 reviews the concepts that are involved in this problem. A ruler is accurate when the temperature is 29.0 °C. When the temperature drops to 18.0 °C, the ruler shrinks and no longer each end so as to stretch it back to its original length. The ruler has a cross-sectional area of 1.26 x 105 m2, and it is expansion is 2.5 x 10 (cy1. What is Young\'s modulus for the material from which the ruler is made? y if a force of magnitude 1.48 x 10 N is applied to made from a material whose coem cent ormear Units

Solution

Contraction L = L .. original length L, exp coeff. , temp drop

Applied force F extends material by L

Young mod (E) = stress / strain = (F/A) / (L/L)

E = (1.48*10^3N / 1.26*10^-5m²) / (L / L) .. .. L cancels out

E = (1.48*10^3N / 1.26*10^-5m²) / (2.5*10^-5°C¹ x 47°C) .. ..

E = 9.99*10^10 N/m² (Pa)