Tiga buah vektor setitik tangkap seperti pada gambar. besar masing masing vektor F1=F2=F3=50N. Tentukan besar resultan ketiga vektor tersebut (a=b=30derajat)
whongaliemdiketahui : F1 = F2 = F3 = 50 N α = β = ditanyakan : R Fx1 = F1.cos α = 50 .cos = 50 . = 25√3 N Fx2 = - F2..cos β = - 50 . = - 25√3 N Fx3 = F3 .cos = 50 . 1 = 50 N ΣFx = 25√3 + - 25√3 + 50 = 50 N Fy1 = F1 .sin = 50 . = 25 N Fy2 = F2 .sin = 50 . = 25 N Fy3 = F3 . sin = 50 . 0 = 0 N ΣFy = 25 + 25 + 0 = 50 N R² = (Σ Fx)² + (Σ Fy)² = 50² + 50² = 2500 + 2500 = 5000 R = √5000 = 50√2 N
α = β =
ditanyakan : R
Fx1 = F1.cos α
= 50 .cos
= 50 .
= 25√3 N
Fx2 = - F2..cos β
= - 50 .
= - 25√3 N
Fx3 = F3 .cos
= 50 . 1
= 50 N
ΣFx = 25√3 + - 25√3 + 50
= 50 N
Fy1 = F1 .sin
= 50 .
= 25 N
Fy2 = F2 .sin
= 50 .
= 25 N
Fy3 = F3 . sin
= 50 . 0
= 0 N
ΣFy = 25 + 25 + 0
= 50 N
R² = (Σ Fx)² + (Σ Fy)²
= 50² + 50²
= 2500 + 2500
= 5000
R = √5000
= 50√2 N