Answer :

(a) Given:

Distance between earth and moon = 60 x earth’s radius

The distance between the earth and moon can be treated as a radius of arc that is subtended by the diameter of the earth from the moon. Let θ be the angle subtended by the arc, R be the earth-moon distance and R_{E} be the earth’s radius. Then,

2R_{E} = length of the arc.

And distance between earth and moon = 60R_{E}

Therefore the angle subtended by the arc

Therefore the diameter of earth as seen from earth will be 2°.

(b) Given:

Diameter of moon as seen from earth =

As calculated before the diameter of earth as seen from moon is approximately 2° and if moon is as seen from earth, then,

Therefore, earth’s diameter is 4 times that of moon’s diameter.

(c) Given:

Distance between sun and earth = 400 x earth-moon distance.

let r_{m �} be the moon’s distance from earth and r_{S} be the sun’s distance from earth, then we have

Let D_{s}, D_{m �} and D_{e} be the diameters of sun, moon and earth respectively. Since we know that the sun and the moon, appear to be the same size from the earth, we have

Also

Therefore, the sun’s diameter is 100 times larger than earth.

Rate this question :

In an experiment Physics - Exemplar

Estimate thNCERT - Physics Part-I

The unit of lengtNCERT - Physics Part-I

(a) How many astrPhysics - Exemplar

A SONAR (soNCERT - Physics Part-I

Einstein’s mass -Physics - Exemplar

Just as preNCERT - Physics Part-I

It is a well-knowNCERT - Physics Part-I

Calculate the lenPhysics - Exemplar

Calculate the solPhysics - Exemplar