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 the interior of Mars compare to that of Earth?
A) Mars's heating rate is 0.125 times that of Earth.
B) Mars's heating rate is 8 times that of Earth.
C) Mars's heating rate is 0.5 times that of Earth.
D) Mars's heating rate is 4 times that of Earth.
E) The heating rates are about the same.

Question

Quizplus · Accepted Answer

The heating rate is related to the volume-to-surface area ratio. Since Mars has a smaller volume relative to its surface area compared to Earth, its heating rate is lower. Given that Mars's diameter is half of Earth's, its volume is 1/8th, and its surface area is 1/4th of Earth's, leading to a heating rate of 0.125 times that of Earth.

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