Question

10. "The figure below shows a uniform rod of length 4L and weight 20 N that is hinged freely at end A to a vertical wall. The rod is kept in equilibrium by a light inextensible string attached t a point at a distance L, from A and a weight of 50 N suspended at end B. String 30° 4 3L 50 N Find (a) the tension of the string. (b) the force exerted by the wall on point A.

Answer 1

Here we use concepts of rotational equilibrium.***************************************************************************************************
This concludes the answers. If there is any mistake, let me know immediately and I will fix it....

Here we use concept of rotational equilibrium a) Torque about A = 0 or, (T sin 60 degree) L - (20 N)(2 L) - (50 N)4 L = 0 or, T = 277 13 N b) F_x = T cos 60 degree = 138.56 N F_y + T sin 60 degree = 20 N + 50 N or F_y = -170 N so, F_A = squareroot F^2_x + F^2_y = 219.32N