Constraint relation in a pulley spring system

In summary: If the center of the pulley moves downward a distance y, and the string is of constant length, how much does the mass move downward relative to the center of the pulley? Relative to the table?In summary, the problem is to find the relationship between the displacements of a block of mass and a pulley of mass. The attempt at a solution assumes tension in both the strings and the pulley. The center of the pulley moves downward a distance y and the mass moves downward relative to the center of the pulley if the string is of constant length.
  • #1
Shivang kohlii
19
1

Homework Statement


1546603482077-1365890843.jpg

How to apply constraints in the system to get a relationship between the displacements of block of mass m and pulley of mass M.?

Homework Equations


T.a= 0

The Attempt at a Solution


Assuming tension in both strings to be T .
-T × a1 ( for the block) + 2T × a2 ( for the strings attached to sides of pulley) + for the string attached from the centre = 0

I can't understand how to proceed
 

Attachments

  • 1546603482077-1365890843.jpg
    1546603482077-1365890843.jpg
    17.3 KB · Views: 1,723
Physics news on Phys.org
  • #2
The place to start on a pulley problem is this the kinematics, not the dynamics. If the center of the pulley moves downward a distance y, and the string is of constant length, how much does the mass move downward relative to the center of the pulley? Relative to the table?
 
  • #3
Shivang kohlii said:
Assuming tension in both strings to be T .
If that were true, why would the pulley rotate?
 
  • #4
haruspex said:
If that were true, why would the pulley rotate?
Why should it rotate ? It's fixed to a table so the tension in both strings should be same
 
  • #5
Chestermiller said:
The place to start on a pulley problem is this the kinematics, not the dynamics. If the center of the pulley moves downward a distance y, and the string is of constant length, how much does the mass move downward relative to the center of the pulley? Relative to the table?
That's the issue .. I don't know how to establish a relation..
 
  • #6
Shivang kohlii said:
Why should it rotate ? It's fixed to a table so the tension in both strings should be same
The pulley doesn't know what the string is attached to. This is not a massless pulley. If the pulley has accelerating rotation, some net torque must cause it. Where is that coming from?
 
  • #7
Shivang kohlii said:
That's the issue .. I don't know how to establish a relation..
Establishing the kinematic relation is a math problem. The length of the rope is constant. This is the constraint you need to use.
 

1. What is a constraint relation in a pulley spring system?

A constraint relation in a pulley spring system refers to the mathematical relationship between the displacement of the pulley and the extension of the spring. This relationship is essential for understanding the behavior and forces involved in the system.

2. How is the constraint relation determined in a pulley spring system?

The constraint relation in a pulley spring system is determined by analyzing the geometry and forces acting on the system. This typically involves drawing free body diagrams and applying Newton's laws of motion to the system.

3. What are the variables involved in the constraint relation of a pulley spring system?

The variables involved in the constraint relation of a pulley spring system include the displacement of the pulley, the extension of the spring, the mass of the objects attached to the system, and the forces acting on the system, such as tension and weight.

4. How does the constraint relation affect the motion of a pulley spring system?

The constraint relation plays a crucial role in determining the motion of a pulley spring system. It helps to calculate the acceleration of the system and the forces involved, which ultimately dictate the direction and speed of the motion.

5. Can the constraint relation in a pulley spring system be modified?

Yes, the constraint relation in a pulley spring system can be modified by changing the geometry or forces acting on the system. For example, altering the position of the pulley or adding additional springs can change the constraint relation and thus affect the behavior of the system.

Similar threads

  • Introductory Physics Homework Help
Replies
27
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
10
Views
3K
  • Introductory Physics Homework Help
Replies
24
Views
1K
  • Introductory Physics Homework Help
Replies
15
Views
2K
  • Introductory Physics Homework Help
2
Replies
52
Views
653
  • Introductory Physics Homework Help
Replies
22
Views
2K
  • Introductory Physics Homework Help
Replies
17
Views
3K
Replies
25
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
801
Back
Top