Prep on Planet Odyssey

 

(a)     arrow towards centre of planet                                                                                      1

(b)     (i)      g = GM/R2 (Do not allow r)                                                                       1

(ii)     gS/gO = R2/25R2; gS = 40/25 (= 1.6 N kg–1)                                               2

(iii)     gC/gO = R2/16R2 giving gS = 40/16 (= 2.5 N kg–1)                                     1