6.2 A composite material consists of parallel fibers of Young's modulus Ef in a matrix of Young's modulus Em. The volume fraction of fibers is Vf. Derive an expression for

Eo. Young's modulus of the composite along the direction of the fibers, in terms of Ef, Em and Vf. Obtain an analogous expression for the density of the composite, pc. Using material parameters given in the next table, find pc and E, for the following composites: (a) carbon fiber-epoxy resin (V = 0.5), (b)glass fiber-polyester resin (V = 0.5), (c) steel-concrete (V = 0.02).