A professor's office door is 0.96m wide, 2.2mhigh, 4.0cm thick; has a mass of 26kg , and pivots on frictionless hinges. A "door closer" is attached to door and the top of the door frame. When the door is open and at rest, the door closer exerts a torque of 5.8N?m .What is the moment of inertia of the door? If you let go of the open door, what is its angular acceleration immediately afterward?