Răspunsuri

2014-05-13T13:10:52+03:00
Sinα=h/l=1/2⇒α=30
miscare uniforma deci a=0
asupra corpului actioneaza N, Ff si G care se descompune dupa cele doua directii
perpendiculare si are valorile Gn = Gcosα=mgcosα, Gt=mgsinα
Ox      Ff-Gt=0 Ff=Gt=mgsinα (1)
Oy      N-Gn=0  N=Gn=mgcos α
 dar Ff=μN=μmgcosα
inlocuim Ff in relatia (1)
μmgcosα=mgsinα⇒μ=sinα/cosα=tg α=tg 30= \sqrt{3} /3=0.57