Is the 4th order Runge-Kutta (RK4) method suitable for a 2nd order linear ODE with dissipative terms modelling free fall of an object through a viscous medium under the action of gravity?
I have used that model, and although the object reached a terminal velocity, the acceleration was nonzero and positive (upwards!), which is really weird. What may be the reason behind this?
I appreciate your effort and contributions.