Two identical satellites, P and Q, orbit the same planet in circular paths of radii r and 2r, respectively.
(i) Explain qualitatively how the orbital speed of a satellite depends on the radius of its orbit around a given planet.
(ii) Without using actual numbers, determine which satellite has greater kinetic energy and by what factor.
(iii) Discuss how the orbital period of Q compares with that of P and justify your answer using appropriate mathematical reasoning.