SOLAR SYSTEM

What is solar system?

The system which is gravitationally bounded system of SUN and objects that revolve about it. In this system, SUN is the major star and planets rotate around it. The solar system was formed after the BIG BANG. There are eight planets that rotate around sun. The age of solar system is 4.568 BILLION YEARS. Planets are named as:

1. Mercury
2. Venus
3. Earth
4. Mars
5. Jupiter
6. Saturn
7. Uranus
8. Neptune

STRUCTURE:

The solar system consists of the SUN, four smaller inner planets surrounded by a belt of asteroids(rocky) and four giant planets and that are surrounded by Kuiper belt. The fundamental component of solar system is SUN that is a low mass star. 

Now we will discuss about sun.

 These are the planets before the asteroid belt.

There are outer planets after the asteroid belt.

SUN:    

Sun is the part of solar system and is one of the most massive components. It covers about 99.86% of the solar system mass. It is at the center of the solar system. Sun is stationary. The sun is not a solid mass. It is made up of Hydrogen, Helium, many heavy elements known as metals and carbon, neon, oxygen and iron. The hottest part of the sun is its core where fusion process occurs. Sun is yellow in colour and has ability to give light. Sun is about four and half billion years old. Sun is a non-living luminous object. 

HOW WAS SUN BORN? 

When a dust cloud and nebula(gas) collapsed under its own gravity then as a result cloud was spread into pieces and as result sun was formed. 

HOW IS ENERGY GENERATED FROM SUN?

In the core of sun, there occurs a process called fusion which converts the hydrogen into helium which generates the energy.

Now we will discuss about planets that revolve around the sun in their fix orbits.

PLANETS:

A large rounded astronomical body that is not a star. These were formed when nebula was collapsed into thin disks. 

Here is the information about each planet.

• Mercury:

It is one of smallest planet that is very close to sun. Its mass is about 3.3011*10^23 kg. It has rocky body. It consists of about 70% metallic and 30% silicate material. Its surface is same as moon, having plains and cratering. The largest known crater is Caloris Planitia. There are two geologically plains on mercury. It is the one of the fastest planet and takes about 88 days to complete its orbit around sun. 

• Venus:

It is second planet from the sun. It is hotter than mercury. It is so bright planet. It is so dry planet and there is no existence of life.  It has yellow white colour. It has molten rocky material. Its mass is about 4.876*10^24 kg. It is made up of iron core and rocky material. Its atmosphere is  mainly nitrogen which is 3%, carbon dioxide which is 96% and some other gases. It is also known as Earth's twin planet.

 

• Earth:

It is third planet from the sun. It is the fifth largest planet in solar system with respect to mass and size. It is the only planet where life is possible. This planet takes about 365 days to complete its rotation around sun. The Earth has only one moon which completes its rotation around earth in 28 or 29 days. About 70% of earth is covered with water. The planet Earth has water, temperature, gravity and atmospheric pressure.  It has oxygen, carbon dioxide, nitrogen, iron and many other gases. Earth is round in shape but not perfectly round. Earth is about 4.543 billion years old. The earth is made up of three layers i.e., crust, mantle and core. The Earth has rocks, oceans, forests, mountains etc. 

• Mars:

It is fourth planet from the sun. It is second smallest planet after mercury. It takes about 687 days for rotation around sun. It contains about 95% carbon dioxide and 1% oxygen. It is also known as RED PLANET. It has two moons. This planet also has Earth like structure. This planet has minerals like silicon, oxygen, metals etc. It has life existing qualities.  

• Jupiter:

This planet is after the asteroid belt and on the fifth number and one of the larger planets. It is gas giant planet, and its mass is more than all other planets. It takes about 12 years to complete rotation. Its atmosphere is composed of mixture of hydrogen, helium, methane and ammonia. It has about 80 moons.  This planet has red spots and stripes. 

Saturn:

This is the number sixth planet. It is second largest planet. It is also gas giant. Its time period for completing orbit is 29years. This planet is not having the solid surface. This planet can float on water as this made up of gases. It is unique among planets as it has thousands of ringlets around it. This is massive ball made up of helium and hydrogen. It has 83 moons.

• Uranus:

This is the number seventh planet. It takes about 84 years to complete the orbit around the sun. It is fourth largest planet in solar system. It is the coldest planet. It has 27 moons. This planet is father of electricity. This planet has set of 13 rings. This consist of rocky material at the core, icy mantle and gaseous crust. This planet was discovered on March 13,1971.

• Neptune: 

This is the last planet from the sun in the solar system. It takes about 165 years to complete the orbit. Its core is made up of iron, nickel and silicates. It is ice giant. Its atmosphere is made up of hydrogen, methane and helium. It has 14 known moons. This planet is life less. It is dark, cold and very windy. 

 

 

BOOK READING

 Book reading is the one of the best habits. It has a lot of positive impacts on person. It has the major role in the developing the one's personality. Book reading takes into another world. Books are one of best friends of humans. The best investment of time is book reading. Through book reading, we gain a lot of valuable knowledge. Books are really a great asset and treasure. 

Advantages of book reading:

It has a lot of benefits.  Through book reading, we learn about different aspects. It enhanced the vocabulary. Through book reading, we come across about stories of different leaders who had work hard in their era to do their best and from this we get motivation to work hard and do our best. 

 Best investment of time: 

There are books on different topics. These includes novels, philosophies, biographies, religious books and stories. Books are for all age groups. Book reading is much better than wasting time here and there and through this we utilize our time in a good and healthy manner. Books help us to know about people of different areas. Book reading help us a lot in gaining knowledge on different topics. Through book reading we come to know about history and origin of every tradition and customs. 

                 THERE IS NO FRIEND AS LOYAL AS A BOOK.

I DO BELIEVE SOMETHING VERY MAGICAL CAN HAPPEN WHEN YOU READ A GOOD BOOK.

Conclusions: 

There is major impact of book reading on the thoughts of man. It is important to choose a good book for reading. It is necessary to develop reading habit. 

SETS

 Sets: - 

The collection of well-defined and distinct objects is called set.

Representation: The sets are represented by capital letters. The curly brackets{} also known as braces are used and elements are enclosed in it.

Examples: Few examples of sets are: 

A={a,b,c,d} 

U={lahore,karachi,jehlem,islamabad}

                                                            Ways of describing a set

There are ways to describe a set.

1. Descriptive Form
2. Tabular Form 
3. Set Builder Notation

                                                            Types of Sets 

Following are the types of sets.

1. Empty Set
2. Singleton Set
3. Finite Set
4. Infinite Set
5. Equal Set
6. Equivalent Set
7. Universal Set
8. Subset
9. Proper Subset
10. Power Set

Definitions of above types of sets.

• Empty Set: The set having no elements is called empty set. A={}
• Singleton Set: The set having only one element is called singleton set. A={a}
• Finite Set: The set having limited number of elements is called finite set. D={a,2,b,4}
• Infinite Set: The set having unlimited number of elements is called infinite set. B={1,2,3,...}
• Equal Sets: Two sets are called equal sets if they have same elements. A={a,b,c} and B={a,b,c}
• Universal Set: The set which has all elements which are consideration is called universal set.
• Subset: A set 'A' is said to be subset of set 'B' if set A has all elements of set B.
• Equivalence Set: Two sets are said to be equivalence set if they have same numbers of elements. A={1,2,3} and B={a,b,c}
• Power Set: A set which has all the subsets including empty set and original set.

NUMBER SYSTEM

 In number system there are various numbers.

• Natural Numbers
• Whole Numbers
• Integers
• Rational Numbers
• Irrational Numbers 
• Real Numbers
• Complex Numbers
• Even Numbers
• Odd Numbers
• Prime Numbers
• Composite Numbers

Now we will discuss the definitions of above one by one

      1.Natural Numbers: 

Natural numbers start from 1. It is denoted by N. 

          N = {1,2,3,...}

     2. Whole Numbers:  

Whole numbers starts from 0. It is denoted by W.

          W = {0,1,2,3,...}

      3. Integers: 

It is denoted by Z. It is the collection of positive and negative numbers with zero. 

          Z = {...,-3,-2,-1,0,1,2,3,...}

      4. Rational Numbers: 

The numbers that can be written in the form of p/q, where p,q are integers and q is non zero.   

   It is denoted by Q.

        

        5. Irrational Numbers: 

The numbers that can not be written in the form p/q. It is denoted by Q'.

         6. Real Numbers: 

 The union of rational and irrational numbers is called real numbers. It is denoted by R.

  

          7. Complex Numbers: 

The number having imaginary part and can be written in the form of "a+ib", where a and b are real numbers and i(iota) is the imaginary number. It can be represented by C. In a+ib, a is real part and ib is imaginary part. 

 

          8.Even Numbers:

The numbers multiples of 2 are even numbers. It is represented by E. 

              E = {0,2,4,6,8,...}

 

           9. Odd Numbers: 

The numbers that are the multiples of 2 are odd numbers. It is represented by O.

              O = {1,3,5,7,...}

 

          10.Prime Numbers 

The number which has only two factors 1 and itself. It is represented by P.

                P= {2,3,5,7,11,...}

2 is the only even prime number.

          

          11. Composite Numbers: 

The numbers other than prime numbers are composite numbers. It is represented by  C. These numbers have more than two factors.

      C = {1,4,6,8,9,...}