Question

Separation between earth and sun is given by 1.5 × 106 km. Time period of another planet is 2.83 year. Find distance of another planet from sun?

• A. 3 × 106 km
• B. 2 × 107 km
• C. 3 × 107 km
• D. 2 × 106 km

Answer 1

Answer: (A)

3 × 106 km

Answer 2

T2 ∝ R3
(T1/T2)2 = (R1/R2)3
$(\frac{1}{2.83})^2$ = {(1.5 x 106)/R2}3
R2 = $(1.5 × 10^{6}) (2.83)\frac{2}{3}$ km
= $(1.5 × 10^{6}) (8)\frac{1}{3}$
= 3 × 106 km

The correct option is (A): 3 × 106 km