What is the binding energy of a body of mass $m$ lying on the surface of the Earth at a distance $r$ from the center of the Earth?

(N/A) The binding energy of a body is defined as the minimum energy required to remove the body from the gravitational influence of the Earth to infinity.
The gravitational potential energy $U$ of a body of mass $m$ at a distance $r$ from the center of the Earth (of mass $M_E$) is given by $U = -\frac{G M_E m}{r}$.
To remove the body to infinity,where the potential energy is zero,we must provide an amount of energy equal to the magnitude of the potential energy.
Therefore,the binding energy $BE = -U = -\left(-\frac{G M_E m}{r}\right) = \frac{G M_E m}{r}$.