Mars has a diameter that is approximately half that of Earth's. If the interiors of these planets are heated by radioactive decays, how does the heating rate of Mars' interior compare to that of Earth's?
A) Mars's heating rate is 0.125 times that of Earth's.
B) Mars's heating rate is 8 times that of the Earth's.
C) Mars's heating rate is 0.5 times that of Earth's.
D) Mars's heating rate is 4 times that of the Earth's.
E) The heating rates are about the same.

Question

Quizplus · Accepted Answer

The heating rate depends on the volume-to-surface area ratio. Mars has a smaller volume relative to its surface area compared to Earth, leading to a lower heating rate, approximately 0.125 times that of Earth's.

Mars Has a Diameter That Is Approximately Half That of Earth's