Which statement correctly describes Newton's second law in terms of acceleration and force?

• A. The net force on an object equals its velocity multiplied by its mass.
• B. Force is equal to mass times distance.
• C. Acceleration is proportional to velocity.
• D. Force equals mass times acceleration.

Answer: (D)

The main idea is that force causes acceleration, with the relationship given by F = m a. This means the net force on an object determines how its velocity changes over time, and the acceleration is directly proportional to the force and inversely proportional to the object's mass. So, pushing with more force makes a given object accelerate more, and a heavier object accelerates less under the same force. The direction of the acceleration matches the direction of the net force.

That’s why the statement with F = m a is correct: force equals mass times acceleration. The other ideas mix up the quantities involved—velocity describes how fast something is moving, not how its speed changes; distance is displacement, not how force relates to motion; and acceleration is about the rate of change of velocity, not velocity itself.