Solution of task 5.2.18 from the collection of Kepe OE

Solution of task 5.2.18 from the collection of Kepe OE

5.2.18
The homogeneous square ABCD platform is fixed horizontally in two hinged vertical bars and is loaded with pairs of forces with moments M1 = 3.2 Nm, M2 = 2.5 Nm and M3. For the case of equilibrium, determine the moment M3. (Use the sum of the projections of the moments on the axis of the AC.)