Which equation is used to express Newton's Second Law of Motion?

• A. F = ma
• B. F = mg
• C. F = mv²
• D. F = W/t

Answer: (A)

Newton's Second Law of Motion is succinctly expressed by the equation F = ma. In this context, 'F' represents the net force acting on an object, 'm' is the mass of the object, and 'a' is the acceleration produced by that force. This law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

The significance of this equation lies in its ability to quantify how the motion of an object changes in response to applied forces. When the net force acting on an object increases while its mass remains constant, the acceleration of the object also increases. Similarly, for a constant force, increasing the mass of the object results in a decrease in acceleration.

The other choices do not accurately represent Newton's Second Law: the equation F = mg specifically describes the weight of an object, which is a force due to gravity, while F = mv² relates to kinetic energy, and F = W/t denotes power, which connects work and time rather than motion dynamics. Therefore, F = ma is the foundational formula for understanding how forces affect motion as described by Newton's Second Law.