The nature of mass, inertia forces, gravity and of centrifugal force, mathematical substantiation of the principle of mach

It is proposed a reasoned Newton's laws, a mathematical proof of Mach's principle, explains the nature of mass, the nature of gravity (weight), the inertia, the cause of their equivalence, the nature of centrifugal force. We give mathematically justified, experimental evidence to support Mach's principle.