two force vectors, f1 18N at 60 degree above the positive axis and F2 6.5N at 45 degree below the positive axis, are applied to a particle at the origin. what third force f3 would make the net force on the particle equal to zero

Answer 1

F1 + F2 + F3 = 0.
F3 = -(F1+F2)
F3 = -(18[E60oN]+6.5[E45oS]) =
-(18*Cos60+18*sin60 +6.5*Cos45+6.5*sin45
= -(9+15.6i + 4.6-4.6i) = -(13.6+11i) =
-13.6 - 11i = 21.6N.[39o] Below the negative X-axis.


f4