Question

Va rog rapidddddd!!!

Answer 1

pt.cazul cand corpul este tras fig.a:

Vectorial:F+N+Ff+G=0

Scalar: Ox:Fcosα-Ff=0=>Fcosα=Ff

            Oy:N+Fsinα-mg=0=>N=mg-Fsinα

Ff=μN<=>Fcosα=μ(mg-Fsinα)=>μ=Fcosα/(mg-Fsinα)=400√3/2/(100*10-400*1/2)=346,41/800=0,43

pt.cazul cand corpul se impinge fig.b:

Vectorial:F+N+G+Ff=0

Scalar: Ox:Fcosα-Ff=0=>Fcosα=Ff

           Oy:N-mg-Fsinα=0=>N=mg+Fsinα

Ff=μN<=>Fcosα=μ(mg+Fsinα)=>μ=Fcosα/(mg+Fsinα)=400√3/2/(100*10+400*1/2)=346,41/1200=0,28

Answer 2

Succes.......................................