This paper discusses the escape velocity for a limited material
distribution in a gravity field. This requeres examining the Newton’s
law of gravitation , the gravitational field vector of a limited material
distribution in a specific point and po
tential function togother with
the potential energy.
In paper, have proved that potential energy vanished in infinity . This
requires also examining Hamilton’s function then we have found the
escape velocity of a material point from a sphere’s surface ,when the
motion of the material point is vertical , horizontal or oblique .
We found the escape velocity for a material point from a disk in the
vertical and oblique cases.
In paper, we also find out the escape velocity from a ring in both
vertical and oblique cases . It is appeared that the escape velocity
from the ring identifies with that we get from the sphere case.
