Newtonian mechanics is a branch of classical mechanics that describes the motion of objects based on the laws of motion and gravitation set forth by Sir Isaac Newton in the 17th century. It is a fundamental theory in physics that explains the behavior of macroscopic objects.
The three laws of motion in Newtonian mechanics are: 1) an object will remain at rest or in motion at a constant velocity unless acted upon by an external force, 2) the force applied to an object is equal to its mass multiplied by its acceleration, and 3) for every action, there is an equal and opposite reaction.
Newtonian mechanics is often referred to as "classical mechanics" because it was the predominant theory of mechanics before the development of quantum mechanics and relativity. It differs from other theories in that it assumes that space and time are absolute and that objects have definite positions and velocities at all times.
No, Newtonian mechanics is a limited theory that is only applicable to objects with speeds that are much slower than the speed of light and are not on a quantum scale. For objects moving at high speeds or in extreme conditions, the laws of relativity and quantum mechanics must be used instead.
Although it has been superseded by more advanced theories, Newtonian mechanics is still used extensively in many fields of science and engineering. It is especially useful for predicting the motion of everyday objects and is the basis for many modern technologies, such as cars, airplanes, and satellites.