What are the constraint forces on a circle with a particle?

Click For Summary

Discussion Overview

The discussion revolves around the concept of constraint forces acting on a particle constrained to move in a circular path. Participants explore different scenarios and interpretations of the question, including the nature of the particle and the forces involved.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants inquire about the nature of the particle and the forces that can act on it, suggesting that a central force may be relevant.
  • One participant notes that the answer depends on how the particle is constrained, providing examples such as a particle on a circular track versus an electron around a charge.
  • There is a suggestion that the original question resembles those found in basic science texts, implying it may be overly simplistic.
  • Another participant expresses confusion regarding the relevance of a diagram provided by the original poster, questioning its connection to the forces in circular motion.
  • One participant attempts to clarify the misunderstanding about circular motion and emphasizes the importance of understanding the forces acting on a string under tension.
  • There are repeated requests for diagrams to illustrate the forces involved, indicating a need for visual representation in the discussion.
  • Some participants express frustration over perceived misunderstandings and insist on the relevance of their questions to the original inquiry.

Areas of Agreement / Disagreement

Participants do not appear to reach a consensus on the nature of the constraint forces or the relevance of the provided diagrams. Multiple competing views and interpretations remain present throughout the discussion.

Contextual Notes

There are indications of misunderstandings regarding circular motion and the forces acting on the particle and string. The discussion includes references to specific scenarios that may not be universally applicable, highlighting the complexity of the topic.

usljoo
Messages
43
Reaction score
0
when a particle is constraint to move on a circle, what are the constraint forces
 
Physics news on Phys.org
when a particle is constraint to move on a circle, what are the constraint forces

What is the particle?

What forces do you know that can act on particles?
Could any of these provide a 'central force'?
 
This depends upon HOW the particle is constrained to move in a circle. If the particle is attached to a circular track, the answer is obvious. If the particle is an electron going around a positive charge, the answer is also obvious but not the same as before.

Frankly, this looks like a question at the end of a chapter of a basic science text- where they are really testing whether you have read the chapter!
 
usljoo said:
when a particle is constraint to move on a circle, what are the constraint forces

usljoo, you know the procedure by now …

you tell us what you think the answer is,

and then we comment! :smile:
 
ok look at the attachment
 

Attachments

my mac doesn't do .doc

how long can it be? :confused: can't you find the time to type it out for us? :redface:
 
i hope ur mac does pdf :P
 

Attachments

i don't understand what your .pdf has to do with the question :confused: …
usljoo said:
when a particle is constraint to move on a circle, what are the constraint forces
 
Looking at your diagram I think I understand your question.

Unfortunately, taking your posts in this thread and your previous one, you seem to have a basic misunderstanding about circular motion.

And this is the reason why it is harder to apply a force like on the picture to a circle of smaller radius and that is because there will be a component of the centripetal force that is opposite to the applied force F on the picture and that’s why torque gets smaller with r.

There is no way that F has anything to do with motion around the circle you have drawn.

None of this is meant as a personal criticism; I really am trying to help.

You did not bother to answer my previous question. All my questions are designed to help and further understanding.

Have a look at this recent thread, where I like to think the OP went away with a better understanding and achieved something for himself.

https://www.physicsforums.com/showthread.php?t=468864

Now just answer this simple question.

If you take a string and pull it out taught so it is under tension, what are the forces acting in the string and on the string?
Can you draw a simple diagram?
 
  • #10
Studiot said:
Looking at your diagram I think I understand your question.

Unfortunately, taking your posts in this thread and your previous one, you seem to have a basic misunderstanding about circular motion.



There is no way that F has anything to do with motion around the circle you have drawn.

None of this is meant as a personal criticism; I really am trying to help.

You did not bother to answer my previous question. All my questions are designed to help and further understanding.

Have a look at this recent thread, where I like to think the OP went away with a better understanding and achieved something for himself.

https://www.physicsforums.com/showthread.php?t=468864

Now just answer this simple question.

If you take a string and pull it out taught so it is under tension, what are the forces acting in the string and on the string?
Can you draw a simple diagram?

the forces on the string are the tension force witch acts on the pivot where you binded the string and the same acts also on your hand but i don't see what this has anything to do witch my question

im asking you under these constraints that i have drawn and when you apply a tangential force F as shown what are the forces of the constraint and how will they affect my force F
 
  • #11
the forces on the string are the tension force witch acts on the pivot

This doesn't make sense. Is the force acting on the string or the pivot? I actually asked about the string.

You really need to pay attention to what is said.

Did you draw a diagram?

And, yes, the question has direct relevance, which will become clear.
 
  • #12
well look man i really am no beginner here and the question is far from trivial so don't ask me these questions about the string because you didnt get my question i think better tell me what the forces of constraints are
 
  • #13
go well
 

Similar threads

Undergrad Constraint Forces and Lagrange Multipliers
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad Bilateral and unilateral constraints
  • · Replies 1 ·
Replies
1
Views
745
Undergrad Virtual work and constraint forces
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Understanding Holonomic Constraints: Common Questions and Answers
  • · Replies 2 ·
Replies
2
Views
2K
Graduate Virtual work of constraint forces in Hamilton’s principle
  • · Replies 7 ·
Replies
7
Views
2K
Undergrad Degrees of freedom and constraints
  • · Replies 2 ·
Replies
2
Views
1K
Undergrad Constraints of a mechanical system
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Virtual displacement is not consistent with constraints
  • · Replies 3 ·
Replies
3
Views
2K
Graduate Hamilton's principle and virtual work by constraint forces
  • · Replies 3 ·
Replies
3
Views
2K
Graduate D'Alembert's principle and the work done by constraint forces
  • · Replies 6 ·
Replies
6
Views
3K