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 coeficient of static friction for all surfaces is 0.4, the minimum force F (in kN) needed to move the block S is

A rigid link PQ of length 2 m rotates about the pinned end Q with a constant angular acceleration of 12 rad/s² . When the angular velocity of the link is 4 rad/s, the magnitude of the resultant acceleration (in m/s² ) of the end P is _______

A pin jointed uniform rigid rod of weight W and length is supported horizontally by an external force F as shown in the figure below. The force F is suddenly removed. At the instant of force removal, the magnitude of vertical reaction developed at the support is

Two steel truss members, AC and BC, each having cross sectional area of 100 mm², are subjected to a horizontal force F as shown in figure. All the joints are hinged.

If F = 1 kN, the magnitude of the vertical reaction force developed at the point B in kN is