Here's why:
* Inertia is the tendency of an object to resist changes in its motion.
* Mass is a measure of the amount of matter in an object.
Think of it this way:
* A large, massive object like a boulder is difficult to move because it has a lot of inertia.
* A small, lightweight object like a feather is easy to move because it has very little inertia.
The relationship between inertia and mass is represented by Newton's First Law of Motion:
An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
This means that the larger the mass of an object, the greater its inertia, and the harder it is to change its motion. Conversely, the smaller the mass, the smaller the inertia, and the easier it is to change its motion.
