Gravity is different from the forces of collisions in three important ways. First, gravity is a noncontact force, which means objects experience the force of gravity without touching any other objects.
Second, gravity is a constant force that exists between two objects, which means gravity is exerted all the time—not just during a fall.
Third, gravity is an attractive force, meaning it is a force that pulls, not a force that pushes. (Collision forces are pushing forces.)
However, there is one way that forces from gravity and forces in collisions are similar: in both cases, objects experience equal and opposite forces. For example, when Earth pulls down on a pod due to gravity, the pod also pulls up on Earth due to the same force. Of course, because Earth is so much more massive than even the heaviest pod, the change caused by the force of the pod pulling up on Earth is so tiny that it’s very hard to detect!
