Newtons first law of motion inertial reference systems

1 Newton s first law of motion inertial reference systems 

Generally speaking, the same physical events can be described differently in different reference systems. Undoubtedly, we would wish to find a reference system in which the laws 

Besides, if one of the reference systems moves relative to another, additional effects can appear. All these questions are the subjects of different theories of relativity, realizing the relationships between physical laws in reference systems moving relative each other (refer to Section 1.6). 

The classical theory of relativity is based on Galileo s and Newton s hypotheses. Their main feature is separation and independence the space and time and their independence. The laws of the classical theory of relativity appear from mankind s everyday experience of isotropic and uniform space (all directions are equivalent and space metric is constant everywhere) and independence of time intervals from the reference system (an interval in Moscow is the same as in London). These laws prove to be perfectly justified in the case of motion of a material body with velocities v c. 

Experiencing no external influences, a free body must, consequently, move rectilinearly and uniformly. However, this cannot be achieved in all reference systems, but only in those that are referred to as inertial systems. A reference system in which a free body of constant mass proceeds with constant velocity is called an inertial reference system. 

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