Question

Calculate the angular diameter ot the Moon with these known tacts: Moon's linear diameter 3480 km Moon's average distance from Earth 384,000 km number of arc seconds in 1 radian 2.06 x 10 A) 31 arc seconds B) 187 arc seconds C) 1750 arc seconds D) 1870 arc seconds

Answer 1

answer D. 1870 arc seconds

Step-by-step explanation:

given data

Moon's diameter d = 3480 km

so radius r = 1740 km

Moon's distance from Earth R = 384,000 km

No of second in 1 radian = 2.06 ×
`10^(5)`

to find out

angular diameter of the Moon

solution

we know that angular radius is

angular radius =
`(r)/(R)`

angular radius =
`(1740)/(384000)`

angular radius = 0.0045 radius

so we can say radius for angular radius = 0.0045 radius

= 2.06 ×
`10^(5)` × 0.0045

= 927

so diameter is = 2 × 927 = 1854 arc s

so it is near about answer D. 1870 arc seconds