The system is released from rest. Determine the force $($magnitude and direction$)$ which block A exerts on block $B$ if $m_A=2kg,m_B=3kg,P=50N,=30,{}_1=0\mathrm{.}70,$ and ${}_2=0\mathrm{.}50,$ where ${}_1$ and ${}_2$ are coefficients of static friction. The corresponding coefficients of kinetic friction are $75$ percent of the respective static values.