Homework #10 Due Wednesday 12/8/10 1. A crosslinked rubber with a density of 1.00 g/cm 3 is composed of segments with a molecular weight of 10,000 g/mol. What is the tensile stress when the sample is stretched to twice its original length at room temperature? 2. You bring you car to a mechanic because you hear a screeching noise coming from under the hood when the car is cold. However, the noise goes away when the car warms up. The mechanic immediately identifies the problem as a loose belt. How did he know? 3. a. Consider a unidirectional continuous fiber composite in which a stress is applied along the fiber direction. What is the relationship between the total applied stress and the stress felt in the fibers and the matrix? In other words, are the fiber and matrix stresses additive or equal? Answer the same question for the strains. b. Based on your answer to part a, explain why the first component (matrix or fiber) to fail is the one with the lower ductility. 4. A composite consists of 60.0% by volume glass fibers in a polyester matrix.
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Strength of materials, Tensile strength, continuous fiber composite