Torque concept

[drgshahbaz1193]

Hi everyone, there is a concept on page 26 that I don't understand about equilibrium. IT says, "the object is either motionless or moving at a constant velocity due to its internal intertia." I understand how if the net torque was 0 the object would be motionless but I don't understandhow it could be moving? Thanks

[mcat_premed3832]

Good question!

Torque force is essentially the force "F" applied times the perpendicular distance from the pivot point.

Of course force "F" is mass times acceleration. So if the acceleration is zero then the force and thus the torque force is zero. So the real question is: under what conditions would the acceleration be zero? Two conditions: (1) the object is not moving (ie. velocity is zero); and (2) the object is moving but with a constant velocity. It is this second situation that also has an acceleration of zero that answers your question.

[drgshahbaz1193]

Wow, thanks a lot. That was really bugging me