Rotation of a body

[basilworks]

Let there be a globe with two axis of rotation, one along its pole and the other perpendicular to the poles. Is there any point on it that remains at rest or atleast instantaneously at rest? Please help me out...

[Potatoman]

If i understood yr question correctly, surely the only point that wouldnt move (at least as much) would be dead in  the centre...?

[SteveD]

I've been trying to get my head round this.

 

Imagine two pieces of string (A and B), each held taut in a vertical plane.  The globe is positioned with string A passing through it from bottom to top.  If the surface of the globe touches string B and string A is rmoved so that the globe "rolls" round string B, the point where the globe touches the string does not move.  It does, of course, because of the thickness of the string.  Imagine that string B is not there and the globe "rolls" round the point where the centre of the string was.  That point of the globe does not move.

 

Have I got it right?

 

[ezapf]

I don't know the plural of axis and I hate to do someones homework, but I agree with potatoman and say the answer is where the axises intersect.

 

SteveD and Basilworks, If you have a globe handy do this, otherwise picture it in your mind:

Hold the globe north up and spin it as the earth really spins. While it is spinning, turn it end over end (south over north, north over south, again and again). You just created a model for illustration.

[BillyBB]

At rest no, not with two axis of rotation. Instantaneously at rest, well all of it.

[Peter Pedant]

yeah point of intersection.

The plural of axis is axes by the way.

Imagine a globe spinnning about one axis, all points on the surface or within the volume are performing circles around the axis, except the points on the axis itself, which are stationary.

Now imagine it spinning around the second axis, teh same observation applies. The points are all going in circdles except the points on that axis.

The only point in common in both systems is the intersection of the axis.

OK its  abit late, but it will almost do as a proof.