Question

macar una din cele 3, sau cele 2 mai simple va rog. dau coroana

Answer 1

60.

Pt.m2:Vectorial:T+N2+G2+Ff2=m2a

Scalar:Ox:m2gsinβ-T-Ff2=m2a

          Oy:N2-m2gcosβ=0=>N2=m2gcosβ

Ff2=μ2N2=μ2m2gcosβ

m2gsinβ-T-μ2m2gcosβ=m2a  (1)

Pt.m1: Vectorial: T+N1+G1+Ff1=m1a

Scalar: Ox:T-Ff1-m1gsinα=m1a

           Oy:N1-m1gcosα=0=>N1=m1gcosα

Ff1=μ1N1=μ1m1gcosα

T-μ1m1gcosα-m1gsinα=m1a   (2)

(1)+(2)=>m2g(sinβ-μ2cosβ)-m1g(sinα+μ1cosα)=(m1+m2)a=>a=g[m2(sinβ-μ2cosβ)-m1(sinα+μ1cosα)]/(m1+m2)

T=m1(a+gsinα+μ1gcosα)

Vectorial:T1+T2+R=0=>R=-(T1+T2);T1⊥T2=>R²=T1²+T2²=2T²

Scalar:R=T√2

61.

Pt.m3:Vectorial:f+G3+N3+Ff3=m3a

Scalar:f-μm3g=m3a  (1)

Pt.m1:F+G1+N1+Ff1+T=m1a

Scalar:F-T-μm1g=m1a  (2)

Pt.m2:Vectorial:T+G2+N2+Ff2+f=m2a

Scalar:T-μm2g-f=m2a  (3)

(1)+(2)+(3)=>F-μ(m1+m2+m3)=(m1+m2+m3)a=>a=-μg+F/(m1+m2+m3)

T=F-m1(a+μg)=F(m2+m3)/(m1+m2+m3)

f=m3(a+μg)

Am facut ultimele doua probleme , calculele le faci tu!