How much will the Coronavirus pandemic expand?

The Covid-19 pandemic is going to provoke a huge global crisis in all fields (humanitarian, social, economic). To evaluate its impact is difficult until the pandemic crisis will be stopped or at least its peak will be reached. In order to contribute to such work, we propose in this study a new estimation-simulation model, as an alternative to those models coming from probabilistic, genetic algorithms or other approach. Inspired by classical mechanic dynamics of systems, our model tries to formalize the dynamics of affected population by Covid-19 pandemic. By using a logistic model, in order to find the main characteristics of the system’s dynamics we resort to the first two differentiate function by time for four basic indicators (variables). Essentially for obtaining a solution to estimate the system’s dynamics, we used a balance equation for the variable of active cases, as the difference between the total number of infected and the sum between the number of healed (recovered) and the number of deaths, on the one hand, and the hypothesis that at the end of pandemic this variable must be zero, on the other hand. Because for this key-variable doesn't exist an analytical solution we used a numerical method to obtain some key-values for it. Finally, based on such methodology we classified the Covid-19 pandemic evolution in four phases.