3 FORCES ACT ON MOVING OBJECT.FIRST FORCE HAS MAGNITUDE OF 80.0N AND DIRECTED DUE NORTH.ANOTHER HAS MAGNITUDE 60.0N AND DIRECTED DUE WEST.WHAT IS THE MAGNITUDE AND DIRECTION OF THIRD FORCE,SUCH THAT THE OBJECT MOVE IN CONSTANT VELOCITY?

Answer 1

F2+F1 = -60 + i80.
F2 + F1 + F3 = 0
-60 + i80 + F3 = 0
F3 = 60 - i80
tanAr = -80/60 = -1.333333
Ar = -53.13 = Reference angle.
A = -53.13 + 360 = 306.87 Deg.
F3 = 60 - i80 = 60 / cos306.87 = 100N. @ 306.87 Deg.