Which law relates force, mass, and acceleration?

• A. Newton's first law
• B. Newton's second law
• C. Law of universal gravitation
• D. Third law of motion

Answer: (B)

Newton's second law is the one that links force, mass, and acceleration. It states that the net force acting on an object equals its mass times its acceleration (F = m a). This means acceleration depends directly on the net force and inversely on the object's mass: with the same force, a lighter object speeds up more; with the same mass, increasing the force increases acceleration. The acceleration points in the direction of the net force, since it shares that direction as a vector quantity. The other laws describe different ideas—motion without net force, action-reaction pairs, or gravity between masses—so they don’t provide the general relationship among force, mass, and acceleration.