[a] Typical fracture toughness parameters for a range of materials at 20C are given in Table 2. By using these data in Table 2, calculate the crack tip plastic zone in acrylic, ABS and polypropylene. Table 2 - Fracture toughness parameters for a range of materials at 20C [b] Based on the calculated data in [a], write a comparison on the crack tip plastic zone of those mentioned materials. [a] Typical fracture toughness parameters for a range of materials at 20C are given in Table 2. By using these data in Table 2, calculate the crack tip plastic zone in acrylic, ABS and polypropylene. Table 2 - Fracture toughness parameters for a range of materials at 20C [b] Based on the calculated data in [a], write a comparison on the crack tip plastic zone of those mentioned materials