# Homework Help: Inserted mass on a rotating ring, problem with solution interpretation

1. Jan 14, 2014

### albandres

1. The problem statement, all variables and given/known data

Its about a system like in picture. I have it solved alredy BUT I still have a problem
After getting the dynamic equation by newtonian and Lagrangian methods I solved one of them making the hipótesis of Little oscillations. This diferential equation has three solutions depending on ω.

http://www.acienciasgalilei.com/public/forobb/galeria/tmp4/a44be89a0d.png [Broken]

2. Relevant equations

The problem is that one of them is: θ=θocosh(Ωt) but when we increase t, θ grows exponetially till the infinite! How can this be posible if this is a solution only suitable for small oscillations?

Thanks!

PD: sorry about my english (Im spanish, and Im very tired now)

Last edited by a moderator: May 6, 2017
2. Jan 15, 2014

### tiny-tim

ola albandres! welcome to pf!
erm

no picture!

it's difficult to say without knowing the set-up, but does this solution represent an unstable equilibrium?