If two forces act in exactly opposite directions, then the magnitude
of the net force is their difference, and the direction of the net force
is the direction of the greater one.
Examples:
10 newtons up, 4 newtons down, net force = 6 newtons up
24 pounds left, 20 pounds right, net force = 4 pounds left
999,999 ounces forward, 1 million ounces backward, net force = 1 ounce backward
