• 2021-04-14
    Which of the following statements is correct ? (1) There are two types of stress, normal stress(σ) and shear stress(τ). (2) On one section, the normal stress(σ) and the shear stress(τ) must be perpendicular to each other. (3) On one section, all the normal stress(σ) must be equal in size and same in the direction. (4) On one section, all the shear stress(τ) must be parallel.