A professor's office door is $0\mathrm{.}92$ mm wide, $2\mathrm{.}0$ mm high, and $4\mathrm{.}0$ cmcm thick; has a mass of $25$ kgkg ; and pivots on frictionless hinges. A "door closer" is attached to the door and the top of the door frame.

Part A

When the door is open and at rest, the door closer exerts a torque of $4\mathrm{.}8$ N$$mN$$m $.$ What is the least force that you need to apply to the door to hold it open?

Express your answer in newtons.