Solution of task 5.5.8 from the collection of Kepe OE

Solution of task 5.5.8 from the collection of Kepe OE

5.5.8
The homogeneous square plate ABCD is fixed in a horizontal position with the help of three vertical rods 1, 2 and 3. Determine the force Q, which should be applied at point A, so that the rod 3 does not load if G = 100 N, a = 1 m. (Answer 100 )