21. The gravitational attraction of any two objects is based on their mass and
distance. The more mass and the closer
the distance, the greater the gravitational
attraction.
mass orbiting around them, but the moon
If two planets have moons of the same
around planet A is closer than the moon
around planet B, based on the
information given, which of the following
must be true?
(1) Planet A is mostly composed of gas.
(2) Planet B is larger than planet A.
(3) The moon around planet B is hollow.
(4) Planet B has a thicker atmosphere
than planet A.
(5) The mass of planet A is greater than
the mass of planet B.