A wire, 20m long is heated from a temperature of 5oC to 55oC. If the change in length is 0.020m, calculate the linear expansivity of the wire
Answer Details
Linear expansivity is a measure of how much a material changes in length when its temperature changes. It is denoted by the Greek letter alpha (α) and is expressed in units of K-1. The formula for linear expansivity is: α = ΔL / (L_i * ΔT) Where: ΔL = change in length L_i = initial length ΔT = change in temperature Using the values given in the question, we have: ΔL = 0.020 m L_i = 20 m ΔT = (55 - 5) = 50 K Substituting these values into the formula, we get: α = 0.020 / (20 * 50) = 2.0 x 10-5 K-1 Therefore, the linear expansivity of the wire is 2.0 x 10-5 K-1. Answer choice (C) is the correct answer.