Vol.2, No 8, 1998 pp. 629 - 634
UDC: 531.011
ONE APROACH
TO THE PROBLEM OF TWO BODIES
Veljko A. Vujičić
Mathematical Institute of Serbian Academy
of Science and Arts,11001 Beograd, P.O. 367, Yugoslavia
Abstract. The motion of two bodies,
viewed as material points, is known in the celestial mechanics as "the
two bodies' problem". Kepler's Laws, Newton's Law of Gravity as well as
Galilee's theorems about the free fall of the body are exactly related
to this problem. In this paper, however, it can be taken as an example
of two material points, but its relation to the above-mentioned laws makes
it a problem of great importance. The formula for the gravitational force
is obtained in the form: F=chi*m1*m2/p
which
obviously differs from the Newton's one. For assumptions which are not
in agreement with the first of Kepler's laws, the formula for F simply
reduces to the Newton's law of gravitation. Under these assumptions an
analytic expression for gravitational "constant" is obtained. It is shown
that the numerical value of k, for all planets of the Sun-system,
is very close to the widely accepted value of gravitational constant.
Two bodies as material points with masses
m1
and m2
are moving towards each other in the plane z = 0 so that the distance between
their centers of inertia is a known function of time p(t).
Key words: Two body problem, gravitational
force, gravitational constant.
JEDAN PRISTUP
PROBLEMU DVA TELA
Razmatra se zadatak određivanja sile uzajamnog
dejstva dva tela - materijalne tačke, čije je me-đusobno rastojanje funkcija
vremena. Pomoću Lagranžovih diferencijalnih jednačina kretanja prve vrste
lako se određuje da je tražena sila obrnuto proporcionalna rastojanju materijalnih
tačaka. U slucaju da posmatrane materijalne tačke pretstavljaju nebeska
tela Sunčevog sistema ovaj zadatak dobija značaj problema dva tela. Nađena
sila F=chi*m1*m2/p
se razlikuje od Njutnove sile gravitacije. Tek za pretpostavku da je pomenuto
rastojanje konstatno, što nije u saglasnosti sa Keplerovim zapažanjima
dobijaju se formule za Njutnovu silu gravitacije i odgovarajuću gravitacionu
konstantu.
Ključne reči: problem dva tela,
gravitaciona sila, gravitaciona konstanta