Definition

Noun: - A fundamental law of classical mechanics: Newton's second law of motion states that the acceleration of an object is directly proportional to the net force acting upon it and inversely proportional to its mass. The direction of the acceleration is in the direction of the net force.

Usage

This term is used in the context of physics to describe and calculate the motion of objects when forces are applied. - It is a core principle for solving dynamics problems. - It is often expressed by the formula F = ma (Force equals mass times acceleration).

Examples

• In a textbook:
• In an explanation:

Advanced Usage

• Mathematical Formulation: The law is precisely defined as the net force F being equal to the time rate of change of linear momentum p (where p = mv). Thus, F = dp/dt = d(mv)/dt. For constant mass, this simplifies to the familiar F = ma.
• Conceptual Application: It explains why objects with different masses fall with the same acceleration in a vacuum (gravity provides a force proportional to mass, so the acceleration, a = F/m, remains constant).

Variants and Related Words

• Newton's second law: A common shortened form.
• Second law of motion: The most concise variant.
• Law of acceleration: A descriptive alternative name.

Synonyms

• Law of force and acceleration: A descriptive synonym.
• Fundamental principle of dynamics: A broader categorical term that includes this law.

Related Phrases

• F = ma: The iconic algebraic equation representing the law for constant mass.
• Net force: The vector sum of all forces acting on an object, which is central to the law's application.
• Rate of change of momentum: The more general, formal statement of the law.

Noun

1. the rate of change of momentum is proportional to the imposed force and goes in the direction of the force