The moon subtends an angle of 57 minutes at the base line equal to radius of earth. What is the distance of moon from earth. Given radius of earth is 6400 km.

Explanation

Here, `theta = 57 min. = (57^@)/(60) = (19)/(20)xx(pi)/(180)rad`
I = radius of earth ` =6400km = 6.4xx10^6m = r = ?`
From `I =r theta, r= (1)/(theta) = (6.4xx10^6x20xx180)/(19xxpi) m = 3.86xx10^8m`