Two Fundamental Features of the Attraction Field

Inasmuch as Equation (1.6) allows us to solve the forward problem for any distribution of masses, we may say in this sense that the theory of the gravitational method is completely developed. However, in order to understand better the behavior of the field of the earth and sometimes to improve the quality of the 

consider the field of an elementary mass and evaluate the integral along the straight line shown in Fig. 1.4a. This gives 

Comparison of Equation (1.16) to Equation (1.17) shows that in both cases the value of the integrals is defined by the distance from the particle to terminal points 

Here dli is the displacement along the radius vector, drawn from the point q, but dl2 is the element of the arc of the radius Lgp. Then we have  

Taking into account the fact that the interval dl is very small, the integral is equal to g(Ain and the right hand side of Equation (1.18) describes this product. Performing a summation of these integrals along the path with terminal points p and p2, we obtain  

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In the previous section we established two fundamental features of the attraction field, and both of them follow from Newton s law of attraction and the principle of... 

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