A ball is tossed straight up from the surface of a small spherical asteroid with no atmosphere. The ball goes to a height equal to the asteroid's radius and then falls straight down towards the surface of the asteroid. What forces if any act on the ball while it is on the way up? a. only a decreasing gravitational forces acts downward
b. Only an increasing gravitational force that acts downwards.
c. only a constant gravitational force that acts downwards
d. Both a constant gravitational force that acts downwards and a decreasing force that acts upwards.
e. No forces act on the ball