[" 17.A satellite "S" is moving in an elliptical orbit around "22" ."],[" the earth.The mass of the satellite is very small "],[" compared to the mass of the earth.Then,"],[" (1) the acceleration of S is always directed towards "],[" (2) the acceleration of S is always directed towards "],[" (2) the angular momentum of S about the centre "],[" ( "2" ) the earth changes in direction,but its "],[" (3) the total mechanical energy of S varies "],[" periodically with time."],[" (4) the linear momentum of S remains constant in "],[" magnitude."]