Suppose I have an object, let's say a stick which is of length, let's say 1 meters. I have most of the mass of the stick concentrated on one side of the stick (the center of mass). Now, if I move the stick, I required more force to move it when I'm holding it near the center of mass than when I hold it farther apart. Why is it so?

Shouldn't I be required to apply more force farther away as I would have the additional mass of the stick to displace?


  • $\begingroup$ "Movement" in this case is a combination of straight-line motion and rotation. Can you clarify if you mean one or the other, or if you mean movement of any kind? $\endgroup$
    – garyp
    Nov 2, 2014 at 14:24
  • $\begingroup$ Any kind really. See, it works both ways: you take a rope and you try to rotate it near the center of mass and farther away from it. Do the same to move an object and it'll be the same thing, why so? $\endgroup$ Nov 2, 2014 at 15:27

1 Answer 1


I guess you are referring to Torque. When you hold the stick far from the center of mass, you need to apply a torque to the stick, because the stick wants to fall AND to rotate. Now when you hold the stick at the center of mass, the stick does not want to rotate. It only wants to fall. So you don't need to try and make it not rotate.

The further you hold it from the center of mass, the more it wants to rotate, it's called moment of inertia.


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