Question

Pentru doua corpuri m1=4kg si m2=2kg,legate printr-un fir,ca in figura de mai jos,si care se misca uniform,determinati tensiunea in fir si coeficientul de frecare.
P.S.Daca se poate sa imi notati ce alte forte actioneaza pe fiecare corp in parte.

Answer 1

$v=const=>a=0\\pt.m1:\vec{N_1}+\vec{G_1}+\vec{F_f}+\vec{T}=0\\Ox:T-F_f=0=>T=F_f\\Oy:N_1-m_1g=0=>N_1=m_1g\\F_f=\mu N_1=\mu m_1g\\T-\mu m_1g=0(1)\\pt.m_2:\vec{T}+\vec{G_2}=0\\Ox:m_2g-T=0(2)\\(1)+(2)=>m_2g-\mu m_1g=0|:g=>m_2=\mu m_1=>\mu=\frac{m_2}{m_1}=\frac{2}{4}=0,5=>\mu=0,5\\ (1)=>T=\mu m_1g=0,5*4*10=20 N=>T=20 N$