Three forces act on a moving object. One force has a magnitude of 80.0 N and is directed due north. Another force has a magnitude of 60.0 N and is directed due west. What must be the magnitude and direction of the third force, such that the object continues to move with a constant velocity?
Force 1 = 80.0 N due north.
Force 2 = 60.0 N due west.
a^2 + b^2 = c^2
Theta = tan^-1(fy/fx)
The Attempt at a Solution
First I started by plotting the problem on a cartesian plane. I then took my known quantities of 80.0 N due north (along the positive y axis) and 60.0 N due west (along the negative x axis) and used pythag to find the net force, the answer of which was 100 N.
I then attempted to find the direction using Theta = tan^-1(fy/fx) = tan^-1(80/60) = 53.13.
My question is, am I right in assuming that I must counteract the first two forces with the third to ensure a constant velocity? If so I would appreciate any help in this regard.