Question

The distance of the moon from the earth is about 60 times the radius of the earth. What will be diameter of the earth (approximately in degrees) as seen from the moon.?

• A. $1^o$.
• B. $2^o$.
• C. $4^o$.
• D. $6^o$.

Answer 1

Answer: (B)

$2^o$.

From figure

We know the formula

$\theta =\frac{Diameterofearth}{R}$

$\theta =\frac{2R_E}{60R_E}$

$=\frac{1}{30}rad=\frac{1}{30}\times \frac{{180}^o}{\pi }=2^o$

The diameter of the earth as seen from the moon is about $2^o$.