Which of the following best describes the law of superposition as it applies to physics?

• A. The net response caused by two or more stimuli is the sum of the responses that would have been caused by each stimulus individually.
• B. The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.
• C. The total energy of a closed system remains constant over time.
• D. The unit of force is defined as $\mathrm{kg}\cdot m/s^2$.

Answer: (A)

Verified step by step guidance

1. Understand that the law of superposition in physics states that when two or more stimuli (such as forces, waves, or fields) act on a system, the total effect is the sum of the individual effects caused by each stimulus separately.
2. Recognize that this principle applies to linear systems where responses add algebraically without interfering with each other.
3. Note that this law is fundamental in areas like wave interference, electric fields, and forces, allowing us to analyze complex interactions by considering simpler individual contributions.
4. Compare the given options and identify that the statement 'The net response caused by two or more stimuli is the sum of the responses that would have been caused by each stimulus individually' directly reflects the law of superposition.
5. Understand that the other options describe different physics principles: Newton's second law, conservation of energy, and the definition of the unit of force, which are unrelated to the law of superposition.