1. Figure 1 shows a robotic arm. Assume that the elbow joint is held rigid, such that 0₂ is constant. The two links, l₁ and l2, are both rigid and massless. There is a pure torque, T,acting at the pin joint.

a. Identify all the forces acting on the system. Draw the free body diagram.

How many degrees-of-freedoms does the system have?

c. Write the position of the endpoint mass, m, relative to the pin.

d. Write the equation of motion for the system.

e. What torque, T, is required to maintain a configuration at angle 0₁