Question: solveing ODE system

Hey

I have this spring setup:

spring setup

 

Now I wan't to analyse the motion of the springs, so i create this equations:

> a := m1*((D@@2)(y1))(t)+k1*y1(t)-k2*(y2(t)-y(1))-F1(t) = 0; > b := m2*((D@@2)(y2))(t)+k2*(y2(t)-y1(t))-k3*(y3(t)-y2(t))-F2(t) = 0; > c := m3*((D@@2)(y3))(t)+k3*(y3(t)-y2(t))-F3(t) = 0;

However when i try to solve the ODE system:

> dsolve([a, b, c], {y1(t), y2(t), y3(t)})

It never stops evaluation

What are i'm doing worng?

spring_ODE_setup.mw

 

Please Wait...