(a) For a fiber-reinforced composite, the efficiency of reinforcement h depends on fiber l...

(a) For a fiber-reinforced composite, the efficiency of reinforcement h depends on fiber length l according to

where x represents the length of the fiber at each end that does not contribute to the load transfer. Make a plot of η versus l to l = 50 mm (2.0 in.), assuming that x = 1.25 mm (0.05 in.).

(b) What length is required for a 0.90 efficiency of reinforcement?