How to model Non linear differential equation in matlab

I want to model the following differential equation using simulink. d2x/dt2=g-C/m(i^2/x^2)* I have modeled it in simulink. but the problem is that at time =0 the reciprocal math function in the feed back loop gives NAN or INF error because at time =0 the output is zero. Kindly help me how can i remove the error or how can i model this differential equation. thanks.

Answer 1

[Mischa Kim]

Khan, simply set the initial condition for x to some value other than zero. You can change initial conditions by double-clicking the corresponding integrator block (Integrator1, in your case).

[Khan 954]

Dear Mischa Kim, it really helped. Thanks for your answer.