What happens when a backward force is greater than a forward force?

• A. The object accelerates forward.
• B. The object disappears.
• C. The object will slow down, stop, and then begin to move in the opposite direction.
• D. The object continues at constant speed.

Answer: (C)

When the net force is directed backward (the backward force outweighs the forward force), the object experiences acceleration in the backward direction. If it’s moving forward to begin with, that backward acceleration slows it down, brings it to a stop, and then, as the backward force continues, it starts moving backward. So the motion follows a sequence of slowing, stopping, and reversing direction. A nonzero net force always changes velocity in the direction of that force, so forward acceleration or constant speed can’t occur under a stronger backward force, and the idea that the object would disappear isn’t physically possible.