Newton’s second law of motion

Definition

Newton’s second law of motion states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. Mathematically, it is represented as $F = ma$, where $F$ is the net force, $m$ is the mass, and $a$ is the acceleration.

5 Must Know Facts For Your Next Test

1. Newton’s second law can be written as the equation $F = ma$.
2. The unit of force in the International System (SI) is the Newton (N).
3. Acceleration occurs in the direction of the net applied force.
4. If multiple forces act on an object, you must sum all forces vectorially to find the net force.
5. The law applies to any direction; forces and accelerations are vector quantities.

Review Questions

• What is the mathematical representation of Newton’s second law of motion?
• How does increasing an object's mass affect its acceleration if a constant force is applied?
• In what direction does an object accelerate according to Newton's second law?

Related terms

Force:

An interaction that changes the motion of an object when unopposed. It has both magnitude and direction.

Mass:

A measure of an object's resistance to acceleration when a force is applied. It also determines the strength of its gravitational attraction.

Acceleration: \text{The rate at which an object changes its velocity. A vector quantity with both magnitude and direction.}