Answer:
Only a decreasing gravitational force that acts downward
Explanation:
The gravitational force is the gravitational pull which attract a mass of smaller size by the mass of a bigger size. It is the force which attract two masses close to each other.
In the context, when a ball is tossed up from the surface of an asteroid that have no atmosphere, the ball rises up and then falls back to the surface of the asteroid. The ball falls back because the gravitational pull of the asteroid pulls back the ball to its surface. Thus a decreasing gravitational force acts on the ball in the downward direction while the ball is in its way up.
