Gravitational Acceleration on Different Planets · PhysicsBowl 2014 #27

Physics · mechanics

Problem

Two spherical, non-rotating planets, X and Y, have the same uniform density

\rho

. Planet X has twice the radius of Planet Y. Let

g_X

and

g_Y

represent the accelerations due to gravity at the surfaces of Planet X and Planet Y, respectively. What is the ratio of

g_X : g_Y

? (A)

2:1

(B)

1:2

(C)

1:1

(D)

4:1

(E)

1:4