Answer:
An object which moves in the positive direction has a positive velocity. If the object is slowing down then its acceleration vector is directed in the opposite direction as its motion (in this case, a negative acceleration).
Explanation:
Assuming that the vectors are acting along the same axis, we
could just simply add or subtract the vectors. Since the F1 is greater than F2,
there would be motion, there would be acceleration, and that the direction of
motion is along the F1.
According to Newton (2nd law), Force = (mass) x (acceleration)
Substitute what we know : Force = (1,000 kg) x (3 m/s²)
Do the arithmetic: Force = 3,000 kg-m/s² = 3,000 newtons