Newton’s laws are the laws of the relationship between the forces acting on a massive body and the movement of the body, this is their interaction; there are 3 of them, and they were first formulated by the English physicist and mathematician Sir Isaac Newton in 1686.
The wording of the law
Newton’s first law says: There are such frames of reference, called inertial, in which bodies move uniformly and rectilinearly if they are not acted upon by any forces or the action of other forces is compensated.
Description of the principle of law
Simply put, the essence of Newton’s first law can be formulated as follows: if we push the cart on an absolutely flat road and imagine that we can neglect the forces of friction of the wheels and air resistance, then it will roll at the same speed for an infinitely long time.
Inertia is the ability of a body to maintain speed both in direction and in magnitude, in the absence of impacts on the body. Newton’s first law is also called the law of inertia.
Before Newton, the law of inertia was formulated in a less clear-cut form by Galileo Galilei. The scientist called inertia “an ineradicable imprinted movement.” Galileo’s law of inertia says: in the absence of external forces, the body either rests or moves uniformly. Newton’s great merit is that he was able to combine Galileo’s principle of relativity, his own works and the work of other scientists in his “Mathematical Principles of Natural Philosophy”.
It is clear that such systems, where the cart was pushed, and it rolled without the action of external forces, in fact, does not exist. Forces always act on bodies, and it is almost impossible to compensate for the effect of these forces.
For example, everything on Earth is in a constant gravity field. When we move (it doesn’t matter if we walk, ride a car or a bicycle), we have to overcome many forces: rolling friction and sliding friction, gravity, Coriolis force.
Newton’s first law – any material point (body) maintains a state of rest or uniform rectilinear motion until the impact from other bodies forces it to change this state.
Newton’s first law of inertia (Galileo derived the law of inertia)
The law of inertia: If there are no external influences on the body, then this body maintains a state of rest or uniform rectilinear motion relative to the Earth.
An inertial frame of reference (IFR) is a system that is either at rest or moving uniformly and rectilinearly relative to some other inertial frame. Those. frame of reference in which Newton’s 1st law is fulfilled.
Body weight is a quantitative measure of its inertia. In SI, it is measured in kilograms.
Force is a quantitative measure of the interaction of bodies. Force is a vector quantity and is measured in newtons (N). A force that produces the same effect on a body as several simultaneously acting forces is called the resultant of these forces.
Formula
There is no formula. The formula for Newton’s first law does not exist.
Newton’s first law contains 2 important statements:
all bodies have the property of inertia;
inertial frames of reference exist.