m=m1+m2=20+30=50 kg
G=G1+G2
Vectorial:F+N+G+Ff=m•a
Scalar:Ox:F-m•g•sinalfa-Ff=m•a
Oy:N-m•g•cosalfa=0=>N=m•g•cosalfa
Ff=μ•N=μ•m•g•cosalfa
F-m•g•sinalfa-μ•m•g•cosalfa=m•a<=>F=m•a+m•g•sinalfa+μ•m•g•cosalfa=50•10+50•9,8/2+0,1•50•9,8•0,866=500+245+42=787 N