Final answer:
To determine the magnitude of the tension force in the deltoid muscle, analyze the forces and use trigonometry to find the y-component of the tension force.
Step-by-step explanation:
To determine the magnitude of the tension force in the deltoid muscle, we can use the given values of l1, l2, and α. First, we need to draw a free-body diagram and identify the forces acting on the arm. These forces include the force of gravity, the tension force (ft), and the applied force (Fapp). Using Newton's laws and the equilibrium conditions ΣFy = 0 and ΣFx = 0, we can find the components of the tension force. Since the x-components of tension cancel out, we focus on the y-components to find the magnitude of the tension force ft. Therefore, the magnitude of the tension force ft in the deltoid muscle can be determined by analyzing the forces and using trigonometry to find the y-component of the tension force. The exact calculation will depend on the specific values given for l1, l2, and α.