Escape velocity at the surface of earth is $11.2\,km/sec$ . If radius of planet is double that of earth but mean density same as that of earth then the escape velocity will be ........ $km/sec$

The orbital angular momentum of a satellite revolving at a distance $r$ from the centre is $L.$  If the distance is increased to $4r$  then the new angular momentum will be

A satellite is moving around the earth with speed $V$ in circular orbit of radius $r$ . If the orbital radius is decreased by $2\%$ , the speed of the satellite will

A geostationary satellite is orbiting the earth at a height of $6\,R$ above the surface of  earth ($R$ is the radius of earth). The time period of another satellite at a height of $2.5\,R$ from the surface of the earth is :-

A skylab of mass $m\,kg$ is first launched from the surface of the earth in a circular orbit of radius $2R$ (from the centre of the earth) and then it is shifted from this circular orbit to another circular orbit of radius $3R$ . The minimum energy required to shift the lab from first orbit to the second orbit are

The kinetic energy needed to project a body of mass $m$ from the earth's surface (radius $R$) to infinity is