## Trajectory Curvature question

Can an object be constructed in such a way that, when thrown WITH rotation in space, causes the object to curve in it's trajectory.
Now, I'm not referring to "curve balls" in baseball, because a curve ball in space will not curve.

Rather, I'm thinking somewhere along the lines of a "dumbell" that has less mass on one side versus the other, and is thrown in space with a rotational moment. Under that condition, I assume the center of mass shifts in a cyclic fashion during rotation, causing the trajectory to trace a sinusodal path. Is that correct?

If that is correct, is there some arrangement of a differential rotating mass that will perform a sustained curve in space as opposed to the above sinusodal motion?
 Recognitions: Gold Member The center of mass will move in a straight line (or parabolic if acted upon by gravity)

 Quote by dav2008 The center of mass will move in a straight line (or parabolic if acted upon by gravity)
You are right, and I can see that my question was not worded correctly and that my use of term center of mass was also used incorrectly.
If you draw a circle around the wrench in your above .gif and place a "dot" at the center of that circle, one can see that the dot takes on a sinusodal motion as it travels the trajectory.
Granted, the center of mass does not "shift" as I erroneously suggested, but the geometrical center does indeed shift during rotation.

So, if I take a metal jar lid, glue a heavy ball bearing to the inside lip, spin it rapidy about the geometric center of the lid(NOT the center of mass) and then force this lid into a linear push across the table, the lid will wobble left and right as it traverses across the table, forming a sinusudal trace about the geometric center.

Perhaps the above description makes more sense as opposed to my incorrect initial question.

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## Trajectory Curvature question

Look up on Eulerian wobbles.

 Quote by arildno Look up on Eulerian wobbles.
OK, thanks, I will. Appreciate the suggestion.

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