Question

which characteristic does inertia describe?
○ how fast an object is moving
○ how difficult it is to change an objects motion
○ how long an object is
○ how large an object is

Explanation:

Inertia is a property of matter that resists changes in motion. It depends on an object's mass and is related to how difficult it is to start, stop, or change the speed or direction of an object's motion.

Answer:

how difficult it is to change an object's motion