The drawing shows the top view of a door that is 1.68 m wide. two forces are applied to the door as indicated. what is the magnitude of the net torque on the door with respect to the hinge?

First, torque is equal to force times the distance. for the first force that is applied, the torque is zero because is applied at the hinge. so the net torque:

t = (12 N) (0 m) (cos 30) + (12 N) (1.68 m) cos 45

t = 14.26 Nm is the torque with respect to the hinge