Mechanical Equilibrium: Rotating w/No Net Torque

Click For Summary
An object rotating with no net torque, such as a sphere spinning about its axis of symmetry, is not considered to be in mechanical equilibrium. This is because mechanical equilibrium requires both net torque and net force to be zero. While an object can be moving through space with constant velocity and no net force, it does not equate to being in equilibrium if it is rotating. The discussion highlights the confusion between rotational motion and translational motion in the context of equilibrium. Therefore, according to the textbook, a spinning sphere is not in mechanical equilibrium.
broegger
Messages
257
Reaction score
0
is an object rotating with no net torque present (such as a sphere spinning about an axis of symmetry) said to be in mechanical equilibrium??
 
Physics news on Phys.org
Originally posted by broegger
is an object rotating with no net torque present (such as a sphere spinning about an axis of symmetry) said to be in mechanical equilibrium??
No, since there could still be a net force acting on the object.
 
my physics book implicitly states that if an object is rotating it is not in mechanical equlibrium - even though there is no net torque and it isn't moving through space (no net force)... but if the same object is moving through space with constant velocity (no net force) without rotating (no net torque) it IS in equilibrium - this is confusing, because to me these two situations are equivalent
 
For a system to be in mechanical equilibrium, the net torque and the net force must be zero.

So assuming these are true, would a sphere spinning about an axis of symmetry be in equilibrium? According to the textbook, no?
 

Similar threads

High School Question about the definition of Torque Equilibrium
  • · Replies 14 ·
Replies
14
Views
1K
What is the relationship between torque and pole placement in rotating objects?
  • · Replies 2 ·
Replies
2
Views
1K
Undergrad How is the net force on the system equal to 0 initially?
  • · Replies 14 ·
Replies
14
Views
1K
Undergrad Effects of External Torques on the Angular Momentum of Asymmetric Bodies
  • · Replies 3 ·
Replies
3
Views
2K
Cantilever equilibrium problem
  • · Replies 53 ·
2
Replies
53
Views
9K
Undergrad The Correlation of Pressure and Torque in Rotational Motion
  • · Replies 4 ·
Replies
4
Views
912
Undergrad Writing an equation for torque around an arbitrary point on a body
  • · Replies 6 ·
Replies
6
Views
1K
Undergrad PIGA: Pendulous Integrating Gyroscopic Accelerometer
  • · Replies 0 ·
Replies
0
Views
1K
High School Static friction needed for rolling without slipping
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Moment of Inertia about an axis and Torque about a point
  • · Replies 5 ·
Replies
5
Views
3K