Physics, asked by yashpal41, 1 year ago

What is parallax method? Derive expression for measuring the distance between earth and sun and also diameter of sun?

Answers

Answered by manishakohli0209
7

Answer:

Parallax is the effect whereby the position or direction of an object appears to differ when viewed from different positions.

Parallax is defined as the apparent shift of a body with respect to another, with the shift of eye.  

The distance between planets and stars from the Earth can’t be measured directly with a metre scale. Hence indirect method called the parallax method is used.  

Explanation:

To measure the distance d of sun (S1) from earth by parallax method, we observe it from two diametrically opposite positions on the earth. A and B on the earth, separated by distance b.  

Measure the angle between two directions along which the sun is viewed at these two points.

Angle= θ = θ1+ θ2

Distance d<<b

b = AB = 2R= 2 * radius of earth

sin θ= θ = b/d

therefore, d= b/ θ  

θ should be measured in radians.

 

Diameter of Sun:

The angular diameter of sun is angle subtended by two diametrically opposite ends of sun at a point on the Earth.

Let, D diameter of Sun and d be distance between sun from the earth. D<<d

Arc length AB=D=d deta θ

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