In case of earth:

A spherically symmetric gravitational system of particles has a mass density, 

$\rho =\left\{\begin{array}{l}{\rho }_0 \mathrm{for} r\le R\\ 0 \mathrm{for} r>R\end{array}\right.$

where ${\rho }_0$ is a constant. A test mass can undergo circular motion under the influence of the gravitational field of particles. Its speed $V$ as a function of distance $r (0<r<\infty )$ from the centre of the system is represented by,

Statement-1: An astronaut in an orbiting space station above the Earth experiences weightlessness.
and

Statement-2: An object moving around the Earth under the influence of Earth's gravitational force is in a state of free-fall.

A thin uniform annular disc (see figure) of mass $M$ has outer radius $4R$ and inner radius $3R$. The work required to take a unit mass from point $P$ on its axis to infinity is: