Mithra Is an Unknown Planet That Has Two Airless Moons

question 32

Multiple Choice

$$\begin{array} { | l | c | c | c | c | } \hline & \text { Mass } & \text { Radius } & \text { Orbital radius } & \text { Orbital period } \\\hline \text { Moon A } & 4.0 \times 10 ^ { 20 } \mathrm {~kg} & \text { unknown } & 2.0 \times 10 ^ { 8 } \mathrm {~m} & 4.0 \times 10 ^ { 6 } \mathrm {~s} \\\hline \text { Moon B } & 1.5 \times 10 ^ { 20 } \mathrm {~kg} & 2.0 \times 10 ^ { 5 } \mathrm {~m} & 3.0 \times 10 ^ { 8 } \mathrm {~m} & \text { unknown } \\\hline\end{array}$$ Mithra is an unknown planet that has two airless moons, A and B, in circular orbits around it. The table summarizes the hypothetical data about these moons. If you dropped a laser at the surface of Moon B, at what rate would it accelerate toward the ground? (G = 6.67 × 10^-11 N ? m²/kg²)

• A)0.10 m/s²
• B)0.15 m/s²
• C)0.20 m/s²
• D)0.25 m/s²
• E)0.30 m/s²