* Newton's Second Law of Motion: This law states that the force needed to accelerate an object is directly proportional to its mass. This means:

* More mass = More force needed

* Less mass = Less force needed

* Inertia: Heavier objects have more inertia, which is their resistance to changes in motion. The more massive an object, the harder it is to start it moving or to stop it once it's in motion.

Example: It's much easier to push a lightweight shopping cart than a heavy refrigerator. The refrigerator has more mass, so it requires a greater force to get it moving.