Understanding Torque: The Role of Axis of Rotation in Force Calculation"

[oneplusone]

Hello,

[1]-Why is it that if you have a force acting upon an object at the point of the axis of torque,
you don't account it in the equation when solving for torque?

Sorry, not really sure how to word it, but ill give it another shot:

You have a long piece of wood on the ground, with many forces acting upon it. On one side of
the wood, you choose the axis of rotation. One of the forces acts on this point at a 42 degree angle.

When calculating the net torque on the object, why do you disregard that force which acts on the point?

Thanks. and let me know if i should try to reword.

 

[SteamKing]

Not making the connection. Perhaps a picture would help.

 

[PhanthomJay]

Torque is calculated about a chosen point on an axis. When the force acts through that point, there is no perpendicular distance from the force to the point.

 

[oneplusone]

Thanks, got it now!