1. The problem statement, all variables and given/known data The parallelogram linkage shown moves in the vertical plane with the uniform 6.8-kg bar EF attached to the plate at E by a pin which is welded both to the plate and to the bar. A torque (not shown) is applied to link AB through its lower pin to drive the links in a clockwise direction. When θ reaches 58°, the links have an angular acceleration and an angular velocity of 6.6 rad/s2 and 2.0 rad/s, respectively. For this instant calculate the magnitudes of the force F and torque M supported by the pin at E. I have attached an image of the question 2. Relevant equations 3. The attempt at a solution On the attached image I've added in red what I believe that forces acting on the system are. But aside from this I'm unsure how else to begin on this problem. I suspect that a normal and tangent coordinate system may be beneficial here but I'm not sure where best to place the origin of the system. Any advice would be appreciated.