The three fundamental laws that form the foundation of classical mechanics, describing how objects move and interact with forces.
An object at rest stays at rest, and an object in motion stays in motion at a constant velocity, unless acted upon by a net external force.
Objects resist changes to their state of motion. This resistance is called inertia, and it is directly proportional to the object's mass. Without a force, nothing changes.
The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.
For every action, there is an equal and opposite reaction. When one object exerts a force on a second object, the second object exerts an equal force back on the first, in the opposite direction.
Fill in any two values and the missing one will be calculated instantly using F = m · a. Leave the value you want to find blank.
Based on Newton's Second Law: F = m · a. Mass must be positive.
Car safety systems — crumple zones, airbags, and ABS brakes — are all designed around Newton's laws to manage forces during collisions.
Every orbital manoeuvre, rocket launch, and satellite trajectory is calculated using Newton's laws of motion and gravitation.
Athletes and coaches use force, momentum, and acceleration analysis to optimise technique in everything from sprinting to ball sports.
Buildings and bridges must balance all forces (gravity, wind, load) so that the net force on the structure is zero — a direct application of the first law.
Aristotle — Believed objects required continuous force to stay in motion. This view dominated for nearly two thousand years.
Copernicus — Published his heliocentric model, challenging the Aristotelian worldview and setting the stage for new mechanics.
Galileo Galilei — Demonstrated that objects in motion tend to stay in motion, laying the groundwork for the concept of inertia.
Isaac Newton — Published Philosophiæ Naturalis Principia Mathematica, presenting the three laws of motion and the law of universal gravitation.
Albert Einstein — Special relativity refined Newton's laws at speeds approaching the speed of light, though Newton's laws remain accurate for everyday speeds.