Time period of 2 disks connected by a spring

AI Thread Summary
The discussion revolves around solving the time period of oscillations for two disks connected by a spring, specifically focusing on case B where the disks rotate in opposite directions. The user is struggling with deriving the angular SHM equation, finding that the angular acceleration is proportional to the cube of angular displacement, which does not conform to SHM. Suggestions were made to improve the clarity of the problem by using LaTeX for equations instead of an unreadable image. The user plans to create a new thread with a clearer representation of the problem. The conversation emphasizes the importance of clear communication in technical discussions.
Vivek33010
Messages
3
Reaction score
2
Homework Statement
2 identical disks (1 & 2) each of mass M and radius R are lying on a flat surface. They are free to rotate about their axis. They are connected by a spring of spring constant 'K'.
Find time period of small oscillations such that :-
Case A: spring 1 and 2 always rotate in same sense.
Case B: spring 1 and 2 always rotate in opposite sense.
Relevant Equations
torque(τ) = (radius vector)×(force vector)
torque(τ) = (moment of inertia I)(angular acceleration α)
Equation of angular SHM, α = -(ω^(2))(θ)
My attempt at solving case B

I've attached my attempt at case B above. What problem I'm facing is that after writing equation of angular SHM, I'm getting angular acceleration proportional to cube of angular displacement, which doesn't reduce to SHM. So how to find time period for this oscillations, or how to reduce it to SHM?Proper diagram with question
 
Physics news on Phys.org
Vivek33010 said:
Homework Statement:: 2 identical disks (1 & 2) each of mass M and radius R are lying on a flat surface. They are free to rotate about their axis. They are connected by a spring of spring constant 'K'.
Find time period of small oscillations such that :-
Case A: spring 1 and 2 always rotate in same sense.
Case B: spring 1 and 2 always rotate in opposite sense.
Relevant Equations:: torque(τ) = (radius vector)×(force vector)
torque(τ) = (moment of inertia I)(angular acceleration α)
Equation of angular SHM, α = -(ω^(2))(θ)

My attempt at solving case B

I've attached my attempt at case B above. What problem I'm facing is that after writing equation of angular SHM, I'm getting angular acceleration proportional to cube of angular displacement, which doesn't reduce to SHM. So how to find time period for this oscillations, or how to reduce it to SHM?Proper diagram with question
Welcome to PF. :smile:

Unfortunately, the image is unreadable. Maybe instead, check out the "LaTeX Guide" link below, and type your work into the Edit window? That makes it a lot easier to read and reply to. Thanks. :smile:

1619022424360.png
 
berkeman said:
Welcome to PF. :smile:

Unfortunately, the image is unreadable. Maybe instead, check out the "LaTeX Guide" link below, and type your work into the Edit window? That makes it a lot easier to read and reply to. Thanks. :smile:

View attachment 281834
I write a new question or just edit this one?
 
You can just reply below with the update to this problem. Or do you mean what you should do if you have a new/different question? In that case please start a new thread. Basically it is one thread per question/problem.
 
berkeman said:
You can just reply below with the update to this problem. Or do you mean what you should do if you have a new/different question? In that case please start a new thread. Basically it is one thread per question/problem.
I'll make a new thread, with the same question, but with better representation. I'll see if I can use latex because I don't know what it is. New thread coming right up
 
  • Like
Likes berkeman
Then I'll close this thread for now. Let me know if you want it back open (send me a message by clicking on my avatar and "Start a Conversation").
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Back
Top