Instantaneous centre of rotation

  • Context: Graduate 
  • Thread starter Thread starter person_random_normal
  • Start date Start date
  • Tags Tags
    Rotation
Click For Summary

Discussion Overview

The discussion revolves around the concept of the instantaneous center of rotation in the context of torque equations, particularly focusing on whether this center can exhibit angular acceleration and the implications of pseudo torque in various scenarios. The scope includes theoretical considerations and conceptual clarifications related to rotational dynamics.

Discussion Character

  • Conceptual clarification, Debate/contested, Technical explanation

Main Points Raised

  • Some participants propose that the instantaneous center of rotation may have angular acceleration, suggesting that it could lead to a pseudo torque term in the torque equation.
  • Others argue that the instantaneous axis of rotation is at rest and not accelerating, indicating that pseudo torque arises only when the point about which torque is calculated is accelerating.
  • A participant questions the conditions under which a bar moving on a frictionless floor, which is both translating and rotating, could have an increasing angular speed, seeking clarification on the forces providing torque and the location of the instantaneous axis of rotation.

Areas of Agreement / Disagreement

Participants express differing views on whether the instantaneous center of rotation can have angular acceleration, leading to a lack of consensus on the implications for torque equations.

Contextual Notes

Limitations include the dependence on specific definitions of instantaneous center and torque, as well as unresolved questions regarding the forces acting on the system and their effects on angular acceleration.

person_random_normal
Messages
165
Reaction score
10
Tell me- in general
It is possible that -while writing torque equation about instant centre of rotation, we may get a pseudo torque term
That is instant centre of rotation may have some angular acceleration
Am I right ?
 
Physics news on Phys.org
Shreyas Samudra said:
Tell me- in general
It is possible that -while writing torque equation about instant centre of rotation, we may get a pseudo torque term

No . Instantaneous axis of rotation means the axis is at rest . It is not accelerating .

Pseudo torque comes in picture when the point about which the torque equation is written is accelerating .
 
Last edited:
what if a bar is moving on frictionless floor (translating + rotating) and such that its angular speed is increasing ,
so instant centre is to have some angular acceleration
 
Shreyas Samudra said:
what if a bar is moving on frictionless floor (translating + rotating) and such that its angular speed is increasing ,
so instant centre is to have some angular acceleration

How is the angular speed increasing ? Which force is providing torque ? Where do you think is the location of instantaneous axis of rotation ?
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 32 ·
2
Replies
32
Views
3K
  • · Replies 10 ·
Replies
10
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 41 ·
2
Replies
41
Views
7K
  • · Replies 60 ·
3
Replies
60
Views
7K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 33 ·
2
Replies
33
Views
4K