Dynamics — Newton’s Laws “The rate of change of momentum of a body is directly proportional to the impressed force and takes place in the same direction as the force.” This statement refers to:

Introduction / Context: Newton’s three laws form the basis of classical mechanics. Each law has a distinct wording and meaning. This question checks recognition of the precise wording of Newton’s second law in its momentum form.

Given Data / Assumptions:

• Momentum p = m * v.
• Force is related to the time rate of change of momentum.

Concept / Approach: Newton’s second law: F ∝ dp/dt and acts in the same direction as dp/dt. In SI units, proportionality becomes equality with F = dp/dt. For constant mass, this reduces to F = m * a.

Step-by-Step Solution:

Verification / Alternative check: First law is inertia (no net force ⇒ velocity constant). Third law describes action–reaction pairs equal and opposite, not rate of change of momentum.

Why Other Options Are Wrong: First law lacks momentum-rate wording; third law relates two interacting bodies, not a single body’s dp/dt; 'None' is unnecessary because the second law fits perfectly.

Common Pitfalls: Confusing momentum form with constant-mass form; forgetting that direction of force equals direction of acceleration and dp/dt.

Final Answer: Newton's second law of motion.