Using the Moon's radius and mass, the Moon's surface gravity is approximately which value?

Using the Moon's radius and mass, the Moon's surface gravity is approximately which value?

• A. 1.6 m/s^2
• B. 2.6 m/s^2
• C. 3.6 m/s^2
• D. 0.6 m/s^2

Answer: (A)

Surface gravity on a spherical body follows g = GM/R^2, where G is the gravitational constant, M is the body’s mass, and R is its radius. For the Moon, using M ≈ 7.35×10^22 kg and R ≈ 1.74×10^6 m, and G ≈ 6.674×10^-11, the calculation gives g ≈ (6.674×10^-11 × 7.35×10^22) / (1.74×10^6)^2 ≈ (4.9×10^12) / (3.0×10^12) ≈ 1.6 m/s^2. So the Moon’s surface gravity is about 1.6 m/s^2, roughly one-sixth of Earth’s gravity. The other values are not consistent with this estimate.

Surface gravity on a spherical body follows g = GM/R^2, where G is the gravitational constant, M is the body’s mass, and R is its radius. For the Moon, using M ≈ 7.35×10^22 kg and R ≈ 1.74×10^6 m, and G ≈ 6.674×10^-11, the calculation gives g ≈ (6.674×10^-11 × 7.35×10^22) / (1.74×10^6)^2 ≈ (4.9×10^12) / (3.0×10^12) ≈ 1.6 m/s^2. So the Moon’s surface gravity is about 1.6 m/s^2, roughly one-sixth of Earth’s gravity. The other values are not consistent with this estimate.