The distance from the moon to the Earth at perigee is about 356 000 km and its distance at apogee is about 406 700 km. Find the eccentricity of the moon's orbit.
A) 0.066
B) 0.058
C) 0.051
D) 0.043
E) none of the above

Question

Quizplus · Accepted Answer

The eccentricity (e) of an orbit is calculated using the formula $e = \frac{d_{apogee} - d_{perigee}}{d_{apogee} + d_{perigee}}$, where $d_{apogee}$ is the distance at apogee and $d_{perigee}$ is the distance at perigee. Substituting the given values, $e = \frac{406700 - 356000}{406700 + 356000} = \frac{50700}{762700} ≈ 0.066$.

The Distance from the Moon to the Earth at Perigee