The three laws of motion, also known as Newton's laws, are the foundational principles of classical mechanics. They state that:
1. An object at rest will remain at rest, and an object in motion will remain in motion at a constant velocity, unless acted upon by an external force.
2. The force acting on an object is equal to its mass times its acceleration, or F=ma.
3. For every action, there is an equal and opposite reaction.
Mass is the measure of the amount of matter in an object, while weight is the measure of the force of gravity acting on an object. Mass is constant regardless of an object's location, but weight can change depending on the strength of gravity in different locations.
Forces can change an object's motion in several ways. If there is no net force acting on an object, it will maintain its current state of motion. If there is a net force, the object will accelerate in the direction of the force. Additionally, forces can also cause objects to change direction or shape.
Balanced forces are equal in magnitude and opposite in direction, resulting in no net force on an object. This means the object's motion will not change. Unbalanced forces, on the other hand, have a net force and will cause an object to accelerate in the direction of the greater force.
The force of an object can be calculated using Newton's second law, F=ma, where F represents force, m represents mass, and a represents acceleration. Force can also be calculated using the formula F=mg, where g represents the acceleration due to gravity (9.8 m/s² on Earth). This applies to objects near the surface of the Earth, but can vary depending on location and altitude.