일반물리학 1 — Gravitation: Problem 61

61 The mean diameters of Mars and Earth are $6.9 \times 10^3 \text{ km}$ and $1.3 \times 10^4 \text{ km}$, respectively. The mass of Mars is $0.11$ times Earth’s mass. (a) What is the ratio of the mean density (mass per unit volume) of Mars to that of Earth? (b) What is the value of the gravitational acceleration on Mars? (c) What is the escape speed on Mars?