Inertia is the property of an object that resists changes to its state of motion. The amount of inertia an object has is primarily determined by its mass. The greater the mass of an object, the greater its inertia. This means that heavier objects are harder to start moving or to stop than lighter ones.
In simple terms, if you think about pushing a car versus pushing a bicycle, you’ll quickly realize that the car’s larger mass means it has more inertia. This principle is foundational in physics and ties directly to Newton’s first law of motion, which states that an object at rest will remain at rest, and an object in motion will stay in motion unless acted upon by an external force.
In summary, the amount of inertia is determined by the object’s mass, and this concept plays a vital role in understanding how objects behave in motion.