An object of mass m is ejected from a satellite revolving around earth at a distance r with constant speed v. If the object excapes from gravitational pull of earth, then the kinetic energy with which the object is thrown is

An object of mass m is ejected from a satellite revolving around earth

1.	An object of mass m is ejected from a satellite revolving around earth at a distance r with constant speed v. If the object excapes from gravitational pull of earth, then the kinetic energy with which the object is thrown is
Answer» `-0.5 mv^(2)` `0.5 mv^(2)` `mv^(2)` `-m v^(2)` Solution :In orbit of satellite `T.E. = P.E. + K.E.` `T.E. = -(GMm)/(2a)` For object to be ejected with velocity v in orbit r T.E. = - K.E. `rarr T.E. = -(1)/(2) mv^(2)` …(i) If we want that the object escapes earth.s GRAVITATIONAL pull, it should be supplied ENERGY that is EQUAL to the NEGATIVE of the total energy. Therefore, energy required to escape `K.E.. = - (T.E.) = (1)/(2) mv^(2)`