Is there a minimum speed an object must reach to be considered in motion?

If a marble took a million years to travel 1" is that in motion or not?Is there a minimum speed an object must reach to be considered in motion?no; there is no minimum speed. it just has to be moving at some sort of velocityIs there a minimum speed an object must reach to be considered in motion?
A million years to travel 1" is hyper-fast compared with the minimum speed.



An object must move at least it's own wavelength in the lifetime of the universe to be considered to be "in motion".



A marble has a mass (for example) of 0.004 kg, and a wavelength of 5.5 x 10^-30 m. The minimum speed would be 1.3 x 10^-47 m/s.



One inch in a million years is 8 x 10^-16 m/s, about 6 x 10^31 times faster.Is there a minimum speed an object must reach to be considered in motion?In physics (mechanics) there is a difference... and a threshold.



There exists two types of friction: static and dynamic. They are not exactly the same (they almost always have different value).



The rule is: when one body is at rest with the support surface (e.g., a box on top of a carpet), you must use the static friction to find out how much minimum force you must apply in order to get the moving moving. In order to do that, you use the weight of the box, the contact area and the coefficient of STATIC friction. This will give you a force. As long as the push is less than that static friction force, the box ain't going nowhere.



Once the box is moving, the friction is calculated using the dynamic coefficient of friction (which may depend on speed -- but it never does for the first homework problems). This also gives a force. The acceleration of the box will depend on the total force applied, minus the dynamic friction force.



Or, as it is used in practice, the force needed to keep the box moving at a steady speed is the same as the dynamic friction force.



For almost all types of material (including cardboard on carpet, for example) the dynamic coefficient is almost always less than the static coefficient. This is why there is often a little "jolt" of acceleration when the box finally gets moving (the resisting force has a sudden drop when it goes from static to dynamic friction).



The difference is due to weak polarity bonds between the "cardboard molecules" and the "carpet molecules" which has time to get themselves set up when the box is stopped but not if the object is moving. (You can picture it as: the molecules will get a better fit between themselves if the box is stopped rather than when it is moving)



As with everything in real life, it is possible to get a speed so low that the polarity bond does have time to set itself every time one molecule passes over another.



This minimum speed changes from object to object (e.g., box-on-carpet will have a different minimum speed than skate-on-ice).



Therefore, it is possible to have a box moving soooo slowly that one must use static friction in the calculation. However, this is known as an unstable equilibrium: as soon as the equilibrium is broken (whatever the cause, for example a drop of butter on the carpet at just the wrong place), the friction goes to dynamic mode and the box immediately accelerates beyond the threshold (because of the "jolt" when the mode changes).



But in theory, the "moving static friction" could exist.



In mechanical physics, such a box would be moving so slowly that it would be considered stopped... even though its position would change with time.



Similar ideas exists in other branches of physics (look up "entaglement" in particle physics) but they are not quite the same.Is there a minimum speed an object must reach to be considered in motion?
an object can be :

1) at rest 2) in motion



even if it's travelling at 0.0000000000000000000000000001 m/s, it's in motion.Is there a minimum speed an object must reach to be considered in motion?Nope...moving is moving, no matter how slowly. If it moves, then when it was in the process of moving, it was in motion.Is there a minimum speed an object must reach to be considered in motion?
Yes it still moved 1". Did it not move if it went from one place to another? The answer is obviously yes.
anything other than 'at rest'....