fiSiCa II

*¿Cual es la fuerza R?A = 100 Cos30 = 86.60

B = 80 Sen30 = 40

C = 40 Cos53 = 26.07

RABC = 150.67


α = 30°
β = 30°
θ = 53°

R = Ax + Ay + Bx + By + Cx + Cy
R = Axі + Ayј - Bxі+ Byј - Cxі - Cyј
R = (Ax – Bx – Cx)і + (Ay + By – Cy)ј

sen α = Ay/A :∙ Ay = A sen α
Ay = 100 (sen 30) = 50 N

cos α = Ax/A :∙ Ax = A cos α
Ax = 100 (cos 30) = 86.6 N

Sen β = Bx/B :∙ Bx = B sen β
Bx = 80 (sen30) = 40 N

cos β = By/B :∙ By = B cos β
By = 80 (cos 30) = 69.28 N

Sen θ = Cy/C :∙ Cy = C sen θ
Cy = 40 (sen 53) = 32 N

cos θ = Cx/C :∙ Cx = C cos θ
Cx = 40 (cos 53) = 24.07 N

∑Vx = (86.6 – 40 – 24.07)
∑Vx = 22.53 N

∑Vy = (50 + 69.28 – 32)
∑Vy = 87.28 NR = 22.53і + 87.28ј

R = √[(22.53)² + (87.28)²]
R = 90.14 N

tgθ = Ry/Rx
θ = tg-1 Ry/Rx
θ = 75.52°