How Do Tension and Spring Forces Work in Different Parts of a String?

AI Thread Summary
Tension in a massless string is uniform throughout, meaning it has the same magnitude at all points along the string. When a force is applied at one end, such as point C, the tension at point A will act to the right, pulling the block of mass m. The tension at the midpoint B will also be directed to the right, as tension acts in both directions along the string. The forces in a spring follow Hooke's Law, which states that the force exerted is proportional to the displacement from its equilibrium position. Understanding these principles clarifies how tension and spring forces operate in various scenarios.
ritwik06
Messages
577
Reaction score
0
I am a bit confused about such forces that act in a string or a spring. I am unable to guess their direction.
Therefor I prepared myslf some examples through which i can understan the concpt of these forces.

In diag1
A force F is applied at end C. What will b the tensions at points A,B(mid point),C. Find their directions and their magnitues. (if the string has no mass)

I can guess about tension at point A. Its going to pull the block of mass m. Therefore, tension will act away in the rightward direction. Am I right? What about the other points?
 

Attachments

  • Diag1.JPG
    Diag1.JPG
    1.5 KB · Views: 507
Physics news on Phys.org
Your attachment doesn't seem to be working. You shouldn't have to guess what direction the opposing force will be applied, it should be easy to realize. A spring will always want to return to its original position.

The equation for this force is: F = -k*dx
 
ritwik06 said:
http://img401.imageshack.us/img401/9550/diag1kw3.jpg
http://g.imageshack.us/g.php?h=401&i=diag1kw3.jpg

A force F is applied at end C. What will b the tensions at points A,B(mid point),C. Find their directions and their magnitues. (if the string has no mass)

I can guess about tension at point A. Its going to pull the block of mass m. Therefore, tension will act away in the rightward direction. Am I right? What about the other points?
 
Last edited by a moderator:
ritwik06 said:
A force F is applied at end C. What will b the tensions at points A,B(mid point),C. Find their directions and their magnitues. (if the string has no mass)

I can guess about tension at point A. Its going to pull the block of mass m. Therefore, tension will act away in the rightward direction. Am I right? What about the other points?

Hi ritwik06! :smile:

A massless string (all strings in exam questions are massless :wink:) has the same tension all the way along. :smile:
 
tiny-tim said:
Hi ritwik06! :smile:

A massless string (all strings in exam questions are massless :wink:) has the same tension all the way along. :smile:

I wish to know their direction dear Tim. :smile:
 
… ah!

ritwik06 said:
I wish to know their direction dear Tim. :smile:

ah … the tension acts in both directions.

Tension is a pair of opposing forces on each tiny little bit of the string. :smile:

(And if the string is massless, the two opposing forces are equal.)

(same with compression)
 

Similar threads

Help again in interpreting a pulley with a spring and a block
2
Replies
52
Views
3K
Confusion regarding surface tension direction and force balance
Replies
39
Views
2K
Force pulling on a string at an angle with a block at the other end
Replies
2
Views
1K
Tension in a string connecting two blocks having equal and opposite velocities
Replies
21
Views
378
Tension in the string while it descends
Replies
8
Views
2K
Tension of string acting on stone moving in horizontal circular motion
Replies
19
Views
3K
Springs and Pulleys - Force analysis
Replies
18
Views
1K
Tension in a deformed cylindrical bag on a surface
Replies
18
Views
1K
How to Calculate Tension Forces in a System?
Replies
4
Views
1K
How can I determine the instant the block overcomes static friction?
2
Replies
61
Views
3K

Hot Threads

Recent Insights

Back
Top