A un estanque de agua en completa calma, se tira una piedra que provoca la formación de ondas circulares concéntricas, cada onda se aleja del centro a una velocidad de 20cm/seg¿con qué velocidad está aumentando la superficie total del agua perturbada al cabo de 8 seg?​

Thats where they was ported and the fields that noone really knew much about needed tended, so they put slaves out there do free work and huge profits and so on the north decided to hold its own and was more different way of survival did not have same climate conditions to afford protecting slaves from winter so expenses be diff from south