Pumping Iron

A human person holds a 20 kg barbell stationary half-way through a 45$^\circ$ curl. The muscle that supports this is connected as shown 5 cm up from the elbow joint. The bone that supports the weight is 25 cm long.

a) Neglecting the mass of the arm itself, find the tension $T$ in the muscle.

b) Find the force $\vec{\bf F}$ exerted on the supporting bone by the elbow joint.