The relationship between inertia and mass is intrinsic, as inertia is the tendency of an object to resist changes in its motion, and this resistance is directly proportional to its mass. Heavier objects have greater mass and thus exhibit greater inertia, making them more difficult to accelerate or decelerate. This principle is fundamental in Newton's laws of motion, where the inertia of an object determines the force needed for changes in speed or direction. Understanding this relationship is essential in physics and engineering applications.