The History of Computers

Computers History:

The computers and machines we are using today are not developed at once.The computer has its various generations as,

(i)First Generation of Computer

(ii)Second Generation of Computer

(iii)Third Generation of Computer

(iv)Fourth Generation of Computer

(v)Fifth Generation of Computer.

 

First calculating device(Abacus):

One of  The simplest and the most earliest calculating device was abacus.Abacus was developed around 300BC. It  was  used to calculate numbers or for additions and subtractions of the numbers.A simple ABACUS is a simple rectangular wooden frame with several parallel wires  and a wire has a number of  beads .These beads are free to slide over the length of the wires vertically when doing additions,counting etc.Each wire of the ABACUS represent a digit.



                           

ABACUS

Abacus was used before the  numbers systems were adopted by merchants,traders,people and sometimes by everyone.Today it is  a part of our museums.But still it is widely used in various parts of world like Asia,Africa,etc.But it is not very common in the world.

Introduction To Importance of Computer Science.

Introduction and Importance:

Computer has always been a powerful tool of calculating information and it is widely is used around the world more frequently and speedily as the time elapsed.

It has now also become the most powerful and amazing powerful medium of sharing information and knowledge around the world.It is also used for communication purposes now a days.Almost every one has a computer and there are millions of  users of computers .

In calculations,computer helps us to do large and tedious calculations in microseconds ,It is widely used by large organizations like banks,military organizations,hospitals,aerospace,research centers,factories as well as home computer users.

Computer Applications in life:

Computer Science education has become a part of the social life.Now-a-days nothing is complete without the help of computer in various applications and aspects of life .For example it is used in hospitals for patients record and many types of computers like patient's blood pressure, heart beat checking machines are widely used in good hospitals.Checking the health of  a critical patient continuously has become impossible without computers and it has removes the need of large number of nurses and doctors looking after a patient in an ICU or Operation theater .

Moral of This Discussion:

Hence,computer science education has become an important part in our daily life.Without computers,the today's world is nothing.But is doesn't  mean that other subjects have no value but instead they all are important in their own way!.

Centrifugal force:

don't be confused with this topic ,

 Simply,

Centripetal Force has come from Latin words (centrum means center and fugree means to flee) it is an outward seeking force.

Definition:

It is the force that moves the body in the outward motion from its circular motion when moving in circle .This force is due to the property of the body called inertia.Centrifugal force is an outward force

 .Some scientists have explained some major concepts about the centrifugal force .

Major concepts:

I. Inertial force

II. Reaction force ,according to the newton 3rd law of motion.

Examples:

The concepts of the centrifugal force is applied to the rotating or moving in circular path,bodies 

such as various machines working on the concept of  centrifugal force.

For example you have a washing machine dryer or cloths dryer at home .It also works on a principle of centrifugal force , motor in the dryer spin the clots at a very high speed that the water inside the wet clots get out through the holes on the body of the dryer , due  the the outward seeking centrifugal force,Thus washing dryers also works on a  principle of centrifugal force.

Centripetal Force

                            What is centripetal force:                                     

Definition:

Generally centripetal force is that force that tends a body to move in a circle or curved path.

It can be defined as 

"The force that tends to move a body in circle is called centripetal force.

or

The center seeking force is called Centripetal force"

Explanation:

Centripetal force is that force that moves a body in circle .For example a stone tied at the end of the string When you move the string the stone tends to move in circle around its axis of rotation.This force is called centripetal force.or The center seeking force is called Centripetal force

Formula:

Here:

Fc is the centripetal force acting on the body

m is the mass of the body

v is the velocity with it is moving

R  is the radius of the orbit.

For example the gravitational  field of earth provide the necessary centripetal force required by the satellites revolving around the earth. 

                                       

According to newton 3rd law there is an reaction to every force, the force opposite to the centripetal force is called Centrifugal Force.It acts opposite to the direction of centripetal force.

Make invisible Ink

Do you want to make a secret letter for someone,a map,a secret message,a secret picture,and so on.
So the question is how to write an invisible message,no doubt you will need an invisible ink that is invisible but appears when needed,I will tell you  how make one

Method 1:

Things you will need:

1. Some lemons.
2.A paint brush.
3.A bowl.
4 a paper to write

What to do:

1 Take the bowl and Squeeze the lemon juice in it.
2.Take the brush and dip it in the lemon juice.
3. Write with the lemon juice on the paper.
4.wait for it to dry and disappear
5.Now,when you want to the message to reappear heat it in front of a bulb or candle flame.

Viola! Your secret is ready.!!!


                     

Make an electromagnetic nail at Home

Things You Will Need:

1.an iron nail
2.about 1 to 1 1/2 feet long copper wire
3. A new battery(The higher voltage the better it is)
4.Some iron made things e.g. paper clips.


What to do:


1.Take the nail and wrap the wire around the nail but leaving some of the part at the end.
The more you wrap the better it will be
2.Now peel the end of the wire at the both ends
4.Now place the two ends at the terminals of the battery.
5.Now place the paper clips at the end tip of the nail you will see that they will stick.


                               Enjoy your own electromagnet







                                                     

                                                                                                                                                                             

Experiments with static electricity

                               

Experiment 1:

What you will need:

1.Balloon
2.Your hair or silk or warm  cloth
3.place near wall

What to do:

1.Take the balloon and rub it with your hair as quickly as possible.
2.make it closer to the wall
3.you will see that it sticks with the wall.

How it works:

*When you rub the balloon with your hair it produces static charge in the balloon which is a negative and when it get closer to the wall it sticks because the wall have + charge and the balloon- the two opposite charge attract each other resulting the balloon to stick.
For best results try on a cold day with less humidity.

Experiment no.2

What you need:

1.A plastic scale(or comb).
2.A piece of paper.
3.A scissor .

What to do:

1.Take the piece of paper and  tear in into small pieces with the scissor.
2.Place the small pieces of paper on a surface.
3.Now rub your scale with your hair for  10 to 15 sec.
4.Now take it closer to the pieces of paper on the surface.

You will see that the pager is trying to stick with the scale .Is it MagiC !!, but The answer is no.

What happened:

*When you rub the scale with your hair it produces static charge in the balloon which is a negative and when it get closer to the piece of paper it sticks because the paper  have + charge and the balloon- the two opposite charge attract each other resulting the balloon to stick.

Now you know that Opposite charges always Attract .