A professor office door is 0.91 meter wide, 2.0 meter high and 4.0 centimeter thick: has a mass 25 kilogram: and pivots on frictionless hinges. A "door closer" is attached to the door and the top of the door frame. When the door is open and at rest, the door closer exerts a torque of 5.2 N•m. Find the least force that you need to apply to door to hold it open?