Talk:Mechanical equilibrium

Untitled

A particle in mechanical equilibrium is undergoing neither linear nor rotational acceleration; however it could be translating or rotating at a constant velocity.

i agree that a constant linear velocity can be there, but is'nt a constant rotational velocity impossible? the scalar speed might stay thesame, however the direction of the speed changes. to achieve this change of direction is nescesary.

am i making some grievous error here? or is the article indeed wrong?

62.45.224.78 (talk) 22:03, 18 February 2008 (UTC)

I introduced "rigid body", in mechanical equilibrium when the sum of all forces on all particles of the system is zero, and also the sum of all torques on all particles of the system is zero.--Patrick (talk) 09:28, 19 February 2008 (UTC)

Not sure how the above is a response to the question... A rotating body can be in equilibrium. Think about spinning a top on a table. Assuming perfect behavior (the top does not move, jump, or slow down in our perfect little world) then there are no unbalanced forces, nor any unbalanced torques. Rotation has its own form of inertia, and kinetic energy can be stored in rotation similarly to it being stored in translation. In any case the equilibrium in question is merely stating that the first derivatives of orientation and location are unchanging (i.e. that no unbalanced forces/torques are acting).

Still not sure if the question is answered. How does

"As applied to a rigid body, the necessary and sufficient conditions become:

A rigid body is in mechanical equilibrium when the sum of all forces on all particles of the system is zero, and also the sum of all torques on all particles of the system is zero."

fit with

"A rigid body in mechanical equilibrium is undergoing neither linear nor rotational acceleration; however it could be translating or rotating at a constant velocity."

when according to my knowledge particles in a uniform rotational orbit has too have av net force pointing toward the center of rotation and therefore is not zero.

--81.225.169.91 (talk) 18:25, 11 January 2011 (UTC)

A static equilibrium is not a frame-invariant concept - one can always switch to a reference from in which a mechanical equilibrium is also a static equilibrium and one can always switch to a reference frame in which a static equilibrium is just a mechanical equilibrium. Equilibrium is a mathematical state in which generalized momentum coordinates are held constant. These don't have to be linear coordinates and they don't have to be angular coordinates, although those are the two most common choices. An object can be in a state of equilibrium with respect to its linear coordinates and not its angular coordinates, or vice-versa. I appreciate this article's clarity and I hope we don't have to sacrifice that for precision - I'll have to see what I can do. JsePrometheus (talk) 19:29, 9 May 2014 (UTC)

Thermodynamics

Should 'Unstable Stability' be directed here, when it plays such an important role in thermodynamics as well? One can watch water slowly boil and see the system at points change from unstable to stable as bubbles nucleate and grow. Geologist (talk) 13:36, 7 January 2012 (UTC)

See also section

Is the link to Water in the "See Also" Section relevant? - Imaginary Pi Slicer (talk) 04:31, 27 November 2012 (UTC)

I went ahead and removed it. Imaginary Pi Slicer (talk) 04:09, 30 November 2012 (UTC)

Requirement to add types of equilibrium.

we have to add a heading named type of mechanical equilibrium, which are stable equilibrium, unstable equilibrium, and neutral equilibrium. AryanpateI (talk) 12:54, 6 September 2023 (UTC)