How does an object’s mass affect its acceleration under the same force?

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Title page of Isaac Newton's Philosophiae Naturalis Principia Mathematica, 1687, featuring large Latin text and publication details in a bordered layout. — Newton’s laws of motion The title page of Isaac Newton's *Philosophiae Naturalis Principia Mathematica* (1687; *Mathematical Principles of Natural Philosophy*), the work in which the physicist introduced his three laws of motion.

According to Newton’s second law, an object's mass and its acceleration are inversely proportional when subjected to the same force. This means that if you apply a constant force to two different objects, the object with the greater mass will experience a smaller acceleration, while the object with the lesser mass will experience a greater acceleration.1

This relationship is defined by the equation $F = m f$ , where $F$ is the force, $m$ is the mass, and $f$ is the acceleration. Because the product of mass and acceleration is determined solely by the applied force, an object with a larger mass requires more force to achieve the same acceleration as a lighter object. Essentially, mass serves as a measure of an object's inertia—its resistance to changes in motion—meaning that for a given force, a higher mass results in a lower rate of acceleration.1