急 ! F5 Variations 1條 7q9

Let P^2 = kR^3 where k is a constant
For the earth, P = 1, R = 1
-> 1^2 = k(1)^3
k = 1
i.e.
P^2 = R^3
-> R = (P^2)^(1/3)
(a)
R(Jupiter)
= [(11.86)^2]^(1/3)
= 5.2 A.U.

(b)
R(Mercury)
= [(87.87/365.26)^2]^(1/3)
= 0.39 A.U.
= 0.39 x 1.496 x 10^8 km
= 5.8 x 10^7 km