A Uniform 13-Kg Trap Door Is Oriented Horizontally and Hinged

Multiple Choice

A uniform 13-kg trap door is oriented horizontally and hinged as shown.What is the magnitude of the torque on the door at the instant that the release is activated and the door can freely rotate?

A) 4.9 N . m
B) 9.8 N . m
C) 48 N . m
D) 72 N . m
E) 96 N .m