F1 = F2 = F3 = F4 ~ F

~> Στ(A) = F.R ~ I.α

= F2.R2 + F3.R3 + F4.R4 ± F1.R1

= F(R2 + R3 + R4 ± R1)

= 10(4 + 6 + 8 ± 0)

= 10.18 ~ 180 N.m searah dgn arah jarum jam ✓✓

~> Στ(D) = F.R ~ I.α

= F4.R4 ± F3.R3 – F1.R1 – F2.R2

= F(R4 ± R3 – R1 – R1)

= 10(2 ± 0 – 2 – 6)

= – 60 N.m berlawanan arah jarum jam ✓✓