Q. 30 The state of stress at a point is given by x=-6MPa, y = 4 MPa and Txy == 8 MPa. The maximum tensile stress (in MPa) at the point is Q. 31 A block R of mass 100 kg is placed on a block S of mass 150 kg as shown in the figure. Block R is tied to the wall by a massless and inextensible string PQ. If the coefficient of static friction for all surfaces is 0.4, the minimum force F (in kN) needed to move the block S is P Q R (A) 0.69 (C) 0.98 S vildatas.com (B) 0.88 (D) 1.37