Question

A satellite with kinetic energy $E$ revolving round the earth in a circular orbit. The minimum additional Kinetic Energy required for it to escape into outer space is:

• A. $\sqrt{2}E$
• B. $2E$
• C. $E/\sqrt{2}$
• D. $E$

Answer 1

Answer: (D)

$E$

For a satellite kinetic energy is given by:

$E=\frac{G{M}_e{M}_s}{2R}$

Total energy of satellite is given by:

$TE=-\frac{G{M}_e{M}_s}{2R}$

Hence, $TE=-KE$

Satellite escapes if an additional energy is provided so that the total energy is zero. Let the additional energy required be $\Delta E$

$TE+\Delta E=0$

$⟹\Delta E=E$