What is the relationship between torque and pole placement in rotating objects?

[fog37]

Hello,

In the same frame of reference and using the same coordinate system , the magnitude of mechanical torque depends on the position of the center of rotation (pole): the lever arm distance varies depending on where the pole is.

For static equilibrium situations, the net torque is zero so as long as all the torques add to zero, it does not matter what each torque magnitude is.

But what if the object is not in rotational equilibrium but spins? Different poles will determine different torques. The location of the pole would seem to affect the situation a lot...not sure about this...

thanks!
fog37

 

[Dr.D]

A figure would certainly help. I have no idea what you are talking about without one.

 

[CWatters]

what if the object is not in rotational equilibrium but spins? Different poles will determine different torques.

A force will produce a different torque about different points (if it's spinning or not).