* The more mass an object has, the more inertia it has.
* The less mass an object has, the less inertia it has.
Here's why:
* Inertia is the resistance to change in motion. It's an object's tendency to stay at rest if it's at rest, or to keep moving at a constant speed and direction if it's already in motion.
* Mass is the amount of matter in an object. Think of it as the "stuff" that makes up the object.
Imagine these scenarios:
* Pushing a shopping cart: A cart full of groceries is much harder to get moving than an empty cart. The heavier cart has more mass and therefore more inertia.
* Stopping a car: A large truck is harder to stop than a small car, even if they're traveling at the same speed. The truck has more mass and therefore more inertia.
* Swinging a baseball bat: A bat with a heavier head is harder to swing quickly than a bat with a lighter head. The heavier bat has more mass and therefore more inertia.
In short: Mass is a measure of the amount of matter, and inertia is a measure of the object's resistance to changes in motion. The more matter there is, the greater the resistance to change in motion.
