The homogeneous rectangular plate weighs 40 lb and is supported in the vertical plane by...

The homogeneous rectangular plate weighs 40 lb and is supported in the vertical plane by the light parallel links shown. If a couple M = 80 lb-ft is applied to the end of link AB with the system initially at rest, calculate the force supported by the pin at C as the plate lifts off its support with θ = 30°.