# Changing equilibrium point in damped simple harmonic motion

1. May 2, 2014

### james6008

Hi

I have a damped simple harmonic motion model and I am altering the input force along with spring constant and damping constant. I can change the damping and spring constant to allow it to oscillate for few seconds before it stops at 0. What parameters do I need to change to alter the equilbrium position from 0 to lets say 10 or 20?

2. May 2, 2014

### paisiello2

Increase the mass or decrease the spring constant. Of course that will change the frequency also.

3. May 2, 2014

### Philip Wood

You could move the mass-spring system (assumed vertical) on to a higher bench. Then the equilibrium point will also be higher. This is a slightly joky answer, but not maliciously so…

Maybe you were looking for something more elaborate, Attach two identical springs to the mass, one running upwards to a support, A, and the other downwards to a support, B. Then the equilibrium position of the mass can be adjusted by moving B (or A) up and down. The effective spring constant will remain constant at twice that of each individual spring, provided the amplitude of oscillations isn't too big. This is what I first thought of, but then I thought: What's the point of all this? Might as well just lift up the whole apparatus...