During a total solar eclips the moon almost entirely covers the sphere of the sun. Write the relation between the distances and sizes of the sun and moon.

It is a well known fact that during a total solar eclipse the disc of the moon almost covers the disc of the sun. Find the approx. diameter of moon from the following data.

A new unit of length is chosen such that the speed of light in vacuum is unity. What is the distance between the Sun and the Earth in terms of the new unit if light takes 8 min and 20 s to cover this distance ?

At the time of solar eclipse,the light from the entire sun is cut off,although its diameter is several hundred times larger than that of the moon.Why?

For the following compound statements, identify the connecting words and then write the component statement : The sun is cold and the moon revolves around the sun.

The earth- moon distance is about 60 earth radius. Moon is seen to be of (1//2)^@ diameter from the earth. From parallax measurement, the sun is found to be at a distance of about 400 times the earth-moon distance. Estimate the ratio of sun earth diameters.

Earth's orbit is an ellipse with eccentricity 0.0167. Thus, earth's distance from the sun and speed as it moves around the sun varies form day to day. This mean s that the length of the solar day is not constant through the year. Assume that earth's spin axis is normal to its orbital plane and find out the length of the shortest and the longesst day. A day should be taken from noon to noon. Does this explain variation of length of the day during the year?

Observe the following facts : (1) The distance from the Earth to the Sun is 149,600,000,000m (2)The speed of light is 300,000,000 m/sec. (3) Thickness of class VII Mathematics book is 20mm (4) The average diameter of a Red Blood cell is 0.00007mm. (5) The thickness of human hair is in the range of 0.005 cm to 0.01 cm. (6) The distance of moon from the Earth is 384,467,000 m. (approx.) (7) The size of a plant cell is 0.00001275m. (8) Average radius of the Sun is 695000km. (9) Mass of propellant in a space shuttle solid rocket booster is 503600kg (10) Thickness of a piece or paper is 0.0016cm. (11) Diameter of a wire on a computer chip is 0.000003m. (12) The height of Mount Everest is 8848m. There some large number like 150,000,000,000m and some every small numbers like 0.000007m. Identify very large and very small numbers from the above facts and write them in the adjacent table.