Question 7
An object moving at 20 m s−1 has two forces acting on it: 12 N along the direction of motion and 12 N opposite to it. What happens to the object?
The right answer is the one marked above.
It keeps moving with uniform velocity. The two forces are equal in magnitude and act in opposite directions, so they cancel each other out:
unbalanced force = 12 N − 12 N = 0
With no unbalanced force, the first law applies — the object keeps the 20 m s−1 it already had.
Forces being present does not by itself mean an object will stop or accelerate. All that matters is their resultant.