For this problem, use FBD and particle kinetics.

Block A is $40kg.$ Block B is $25kg.$ A force of $F=200N$ is applied to block $B.$ If you know that block $B$ does slide on the ground, but you don't know whether block A slips on $B$ or moves with $B.$ Calculate:

a$)$ the acceleration of block $B$

b$)$ the acceleration of block $A$

c$)$ the force of friction between block A and $B$

Between block A and B:

${}_s=0\mathrm{.}30$

${}_k=0\mathrm{.}20$

Between block B and the ground:

${}_k=0\mathrm{.}15$