ASVAB Practice

Newton's Laws of Motion

First Law (Inertia): An object at rest stays at rest; an object in motion continues at constant velocity — unless acted on by a net external force. More mass = more inertia.

Second Law: F = ma (Net force = mass × acceleration). Larger force → more acceleration. More mass → less acceleration for the same force. Measured in Newtons (N).

Third Law: For every action there is an equal and opposite reaction. Forces always occur in pairs, acting on different objects.

Weight vs. Mass: Mass = amount of matter (kg). Weight = gravitational force on that mass (N). W = mg, where g ≈ 9.8 m/s².