Solving the Problem of Calculating Force and Torque on a Door

[asura]

Problem:

A force is applied to a door at an angle of 55.4° and 0.33 m from the hinge.
(a) What force produces a torque with a magnitude of 2.12 N·m?
(b) How large is the maximum torque this force can exert?

Relevant Equations:
T=Fd

My Attempt
I could do part a (force is 7.8 N), but I don't understand how to do part b. How do you determine maximum torque when you only have the force?

 

[Dick]

If you know the magnitude of the force, the only things left to change are the angle or the distance from the hinge. If you change the distance, there is no maximum so I'm guessing you'll want to consider which angle produces maximum torque. But that's only a guess. Another badly written question.

 

[xiiwoman]

Torque

do you go to Glen A Wilson from hacienda heights?