A satellite of mass m is revolving in a stable circular orbit of radius r around the Earth of mass M. Answer the following questions briefly but with clear reasoning.
a. (i) Explain why the total mechanical energy E of the satellite–Earth system is negative even though its kinetic energy is positive.
b. (ii) Show, without performing any numerical calculation, that the magnitude of the kinetic energy of the satellite is half the magnitude of its potential energy in the orbit.
c. (iii) Interpret the physical meaning of parts (i) and (ii) in the context of the satellite being gravitationally bound to the Earth.