Equilibrium: A gymnast is struggling performing a ring routine. He is isometrically attempting to hold the $$iron cross$$ position with his arms at $15$ degrees above the horizontal. The length of his arm is $0\mathrm{.}6$ m $($COM halfway along its length$)$ and has a mass of $3\mathrm{.}5$ kg$.$ The rope of the rings are $10$ degrees off vertical and have a tension of $400$ N$.$ You may assume his whole arm is a one rigid body and that the direction of force application of the ring on his hands is in the direction of the rope.