Forces that act in equal and opposite directions on an object

How is the gravitational force related to the distance between two objects?

Aperson walks first at a constant speed of 4.89 m/s along a straight line from point a to point b and then back along the line from b to a at a constant speed of 2.95 m/s. what is the average speed over the entire trip?

Two point charges are separated by a certain distance. how does the strength of the electric field produced by the first charge