Matthew throws a ball straight up into the air. it rises for a period of time and then begins to drop. at which points in the ball’s journey will gravity be the greatest force acting on the ball?

Force due to gravity will be maximum when ball is nearest to the surface of Earth

Explanation:

As we know that the force due to gravity is given by

here

m = mass of object

g = acceleration due to gravity of earth

here acceleration due to gravity of earth varies with height from the surface and given as

so as object moves away from the surface of earth the force of gravity will decreases and when object is nearest to the surface then it is maximum