1. Mass: This is the fundamental property of matter. The more massive an object is, the more inertia it has, meaning it resists changes in motion more strongly. Think of a bowling ball versus a feather - the bowling ball has much more mass and therefore more inertia.
2. Distribution of Mass: Even with the same total mass, the way that mass is distributed within an object can affect its inertia. A solid sphere will have different inertia than a hollow sphere of the same mass. This is because the mass is concentrated differently, affecting how it responds to changes in motion.
So, while mass is the primary factor, the distribution of that mass also plays a role in determining an object's inertia.
