Newton called weight amount of matter. Now it is defined as a measure of inertness of ph. the subject is heavier, the it is more difficult to give it acceleration. To find inert body weight, compare pressure put by it upon a support surface to a standard, enter a measurement scale. For calculation of mass of celestial bodies use a gravimetric method.
Instruction
1. All bodies having weight excite gravitational fields in surrounding space just as electrically charged particles form around themselves electrostatic field. It is possible to assume that bodies bear in themselves the gravitational charge similar electric, or, in a different way, have gravitational weight. With high precision it was established that inert and gravitational masses coincides.
2. Let there are two dot bodies the mass of m1 and m2. They are removed from each other on r distance. Then force of a gravitational attraction between them is equal: F=C · m1 · m2/r², where With – coefficient which depends only on the chosen units of measure.
3. If on the Earth's surface there is a small body, its sizes and weight can be neglected since Earth dimensions much more surpass them. When determining distance between the planet and a superficial body only Earth radius since height of arrangement of a body is negligible in comparison with it is considered. It turns out that Earth attracts a body with a force of F=M/R² where M – the mass of Earth, R – its radius.
4. According to the law of universal gravitation, acceleration of bodies at gravity on the Earth's surface is equal: g=G • M/R². Here G is the gravitational constant in number equal about 6,6742•10^ (−11).
5. Acceleration of gravity of g and radius of the earth of R are from direct measurements. Constant G with a big accuracy is defined in Kevendish and Yolli's experiments. So, mass of Earth of M=5.976•10^27 of ≈ 6•10^27 of g.