Jawabanmu

2014-09-10T19:03:23+07:00
Dik
F1 = 5 N
F2 = 12 N
α  = 60
R =?

R^2 = F1^2 + F2^2  +  2.F1.F2.cos 60
R^2 = 5^2 + 12^2  + 2. 5.12.0,5
R^2 = 25 + 144 + 60
R^2 = 229
R    = √229
R   = 15 ,13 satuan


semoga membantu