The coefficient of kinetic friction between the surface and the largest block is 0.20, and the coefficient of kinetic friction between the surface and the smaller block is 0.40. If F=25 N and M=4.0kg in the figure, what is the tension (in N) on the connecting string

The coefficient of kinetic friction between the surface and the largest block is 020 and the coefficient of kinetic friction between the surface and the smaller class=