Which law is associated with the equation F = m a?

Which law is associated with the equation F = m a?

• A. Newton's Third Law of Motion
• B. The Law of Gravity
• C. Newton's Second Law of Motion
• D. The Law of Inertia

Answer: (C)

This question tests how motion responds to forces. The equation F = m a says that the net force acting on an object equals its mass times its acceleration. It means that the force governs how quickly the object speeds up or slows down, and that acceleration grows with force but shrinks with greater mass. The direction of acceleration is the same as the net force, so pushing harder or in a different direction changes both how fast and where the object goes. If there’s no net force, acceleration is zero and the object keeps doing what it’s doing (staying still or moving at constant speed). The other ideas don’t fit this specific relation. The Law of Gravity describes how gravity pulls on objects (a specific force) but isn’t the general rule linking all forces to motion. Newton’s Third Law is about action–reaction pairs, not how a single force changes motion. The Law of Inertia (Newton’s First Law) describes resistance to changes in motion, not the quantitative link between force, mass, and acceleration.

This question tests how motion responds to forces. The equation F = m a says that the net force acting on an object equals its mass times its acceleration. It means that the force governs how quickly the object speeds up or slows down, and that acceleration grows with force but shrinks with greater mass. The direction of acceleration is the same as the net force, so pushing harder or in a different direction changes both how fast and where the object goes. If there’s no net force, acceleration is zero and the object keeps doing what it’s doing (staying still or moving at constant speed).

The other ideas don’t fit this specific relation. The Law of Gravity describes how gravity pulls on objects (a specific force) but isn’t the general rule linking all forces to motion. Newton’s Third Law is about action–reaction pairs, not how a single force changes motion. The Law of Inertia (Newton’s First Law) describes resistance to changes in motion, not the quantitative link between force, mass, and acceleration.