Question

the angle of the parallax of a distant star is is to be 10 to the power minus 5 Radian when measured from two points of earth six-month apart the distance of the star from the Earth is

Answer 1

The angle is given as 1 minute. We need to convert that into radians.

Hence, Ɵ = 1/60 * ∏ / 180

Diameter of the earth = l = 2 * radius of the earth = 2 * 6400 * 103 m

Distance of the heavenly body from the centre of the earth = r = l/ Ɵ

r = 2 * 6400 * 103 / 1/60 * ∏ / 180

 = 2 * 6400 * 103 * 60 * 180 /  ∏

 = 4.4 * 1010 m

We know that 1 AU = 1.5 * 1011 m

Hence, r = 4.4 * 1010 / 1.5 * 1011 = 0.29 AU