According to Newton's first law of motion, a force equal to the force keeping the object at rest, but in the opposite direction is what's required to slow an object down.
Newton's First Law of Motion claims: "An object in motion will, in the absence of forces, tend to remain in motion with neither the speed nor direction changing"
Most things on earth tend to actually slow down AND THEN proceed to stop. However; when we consider the situation alone, we can see that there are lots of forces tending to slow the object/s down. Like, friction. Or air resistance.
