16. 截面為100 mm × 100 mm 之正方形截面桿件受到壓力 F = 40 kN 作用,如圖(十四)所示, 斜截面pq上之正交應力,剪應力τ為何? (A) = 1 MPa(壓),τ = √3 MPa (B) = 2 MPa(壓),τ = √3 MPa (C) = 2√3 MPa(壓),τ = -√3 MPa (D) = 3 MPa(壓),τ = -√3 MPa