Advertisements
Advertisements
प्रश्न
Mars has approximately half of the earth’s diameter. When it is closest to the earth it is at about 1/2 A.U. from the earth. Calculate what size it will appear when seen through the same telescope.
उत्तर
Given that `D_("mars")/D_("earth") = 1/2` .....(i)
Where D represents the diameter.
We know that, `D_("earth")/D_("sun") = 1/100`
∴ `D_("mars")/D_("sun") = 1/2 xx 1/100` ......[From equation (i)]
At 1 A.U sun's diameter = `(1/2)^circ`
∴ Diameter of mars = `1/2 xx 1/200 = (1/400)^circ`
At `1/2` A.u, Mar's diameter
= `1/400 xx 2^circ = (1/200)^circ`
With 100 magnification mar's diameter
= `1/200 xx 100^circ = (1/2)^circ` = 30
This is larger than the resolution limit due to atmosphere fluctuations.
Hence, it looks magnified.
APPEARS IN
संबंधित प्रश्न
The nearest star to our solar system is 4.29 light years away. How much is this distance in terms of parsecs? How much parallax would this star (named Alpha Centauri) show when viewed from two locations of the Earth six months apart in its orbit around the Sun?
Exercise
Answer the following question.
Star A is farther than star B. Which star will have a large parallax angle?
500 gm = ______ kilogram.
Arbaz plans to tile his kitchen floor with green square tiles. Each side of the tile is 10 cm. His kitchen is 220 cm in length and 180 cm wide. How many tiles will he need?
You can play this game on the ground. Make two squares of one square meter each. Divide your class into two teams. Ready to play!
- How many of you can stand in it?
So Anar also tried many different ways to make a boundary for 800 square meters of land.
He made rectangles A, B, and C of different sizes. Find out the length of the boundary of each. How much gold wire will he get for these rectangles?
- A
Gold wire for A = _________ metres - B
Gold wire for B = _________ metres - C
Gold wire for C = __________ metres
But then Anar made an even longer rectangle... See how long!
- D
So he will get __________ metres of gold wire!!
Length is ______.
In an experiment to estimate the size of a molecule of oleic acid 1 mL of oleic acid is dissolved in 19 mL of alcohol. Then 1 mL of this solution is diluted to 20 mL by adding alcohol. Now 1 drop of this diluted solution is placed on water in a shallow trough. The solution spreads over the surface of water forming one molecule thick layer. Now, lycopodium powder is sprinkled evenly over the film and its diameter is measured. Knowing the volume of the drop and area of the film we can calculate the thickness of the film which will give us the size of oleic acid molecule.
Read the passage carefully and answer the following questions:
- Why do we dissolve oleic acid in alcohol?
- What is the role of lycopodium powder?
- What would be the volume of oleic acid in each mL of solution prepared?
- How will you calculate the volume of n drops of this solution of oleic acid?
- What will be the volume of oleic acid in one drop of this solution?
Consider a sunlike star at a distance of 2 parsecs. When it is seen through a telescope with 100 magnification, what should be the angular size of the star? Sun appears to be (1/2)° from the earth. Due to atmospheric fluctuations, eye can’t resolve objects smaller than 1 arc minute.
