A professor's office door is 0.95 {\rm m} wide, 2.0 {\rm m} high, and 4.0 {\rm cm} thick; has a mass of 25 {\rm kg}; and pivots on frictionless...

A professor's office door is 0.95 {rm m} wide, 2.0 {rm m} high, and 4.0 {rm cm} thick; has a mass of 25 {rm kg}; 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 4.8 {rm N} cdot {rm m}. What is the least force that you need to apply to the door to hold it open?