8. For an aligned glass fiber-epoxy matrix composite, the average fiber diameter is 0.009mm and fiber length is 2.41mm. In addition, the fiber-matrix bond strength is 73MPa, the fracture strength of the fibers is 3450MPa and the matrix stress at fiber failure is 7.60MPa. If the tensile strength of this compoite is found as 1.42GPa, calculate the volume fraction of fibers. (15 pts)