Nervous System in Humans

March 14, 2024March 14, 2024

Hello friends,

In this post, we are going to explore the “Nervous System in Humans”. This system is like the body’s communication network, controlling everything we do. It’s made up of the brain, spinal cord, and nerves, working together to send messages throughout our body. The Nervous System in Humans plays a crucial role in how we move, think, and feel. Let’s explore this intricate system and understand how it orchestrates the symphony of our daily activities.

What happens when you are in contact with something very hot?

You pull your hands back in order to prevent your skin burn.

What do you do when you hear something very loud?

You cover your ears for comfort.

What do you do when there is a bad smell in your environment?

You cover your nose in order to get away from those smells and relief your nose.

What do you do when there is a very luminous object in front of your eyes?

You close your eyes in order to prevent eye damage and pain in eyes.

Have you noticed in the above context that an organ that is afflicted (in trouble) at a particular time is automatically being relieved by your actions? Well, these actions that you do to relief yourself at a particular time are controlled by your brain; whereas these weird happenings (sudden changes in the environment: hot things, loud sounds & bad smells) are called stimuli (singular: stimulus). The organs that are involved in the process of stimuli are controlled by your nervous system.

Therefore, we can say that, many organs work together to respond to the stimuli and the nervous system controls these organs.

KEY NOTES

An impulsive change in the environment of an organism that starts a reaction with the organism is the stimulus. For example – hearing loud sounds, sensing bad smells and being exposed to too hot or too cold things.
The reaction of the organism to the stimuli is the response.
Dealing with stimuli is all controlled by your brain.
There are 11 organ systems in human body.
External stimuli: the stimuli caused by external factors. E.g. other living things or non-living like water, heat, temperature change, dust and chemicals
Internal stimuli: the stimuli originating inside the organism’s body. E.g. sensation of thirst, hunger and pain.

NERVE CELL OR NEURON

Neuron is the basic structural and functional unit of nervous system.

It is the longest cell of human body
Human brain has an estimate of about 100 billion neurons
Messages are received and sent through neurons spread in the whole body

STRUCTURE OF A NEURON

1) Neuron: A specialized cell that helps in receiving messages from one part of your body and transferring them to other parts is a nerve cell or a neuron. It has three main parts → cell body, axon and dendrites.

2) Cyton (cell body/soma): is a cell body that contains the nucleus and is present in each neuron.

3) Dendrons & Dendrites: Dendrons are short fibres that originate in the cyton (cell body) and further divide into dendrites (smaller dendrons) forming a network of fibres. Dendrites are responsible to receive messages from other nerve cells, and pass them to another neuron.

4) Axon (longest Dendron): The axon is a single long fibre that originates from one side of the cyton. The axon is responsible to carry the messages received by the dendrons and dendrites from one neuron to another. The axon is covered with a sheath known as the myelin sheath.

5) Myelin sheath: it helps to protect the axon.

6) Schwann’s cells: another protective covering of the axon above the myelin sheath acts as a support.

7) Impulse: A chemical disturbance like an electrical signal that helps to transfer the messages along the neuron in the form of a wave is an impulse. In biology, a message is an impulse.

SYNAPSE

Neurons are not in direct contact with each other in order to transfer the messages. In this case, the synapse acts as a gap between the two neurons and helps in transfer of message. Synapse is the junction (or gap) between the two neurons, which transfers message from the axon ending of one neuron to the dendrites of another neuron.

NERVES

Many neurons join together to form nerve fibres and many nerve fibres join (end-to-end) to form a nerve.

TYPES OF NERVES (TYPE 1 → sensory, motor and mixed; TYPE 2 → cranial and spinal)

TYPE 1 (depending upon the direction in which they transfer the impulse)

Sensory Nerves (contain only sensory fibres): they are the nerves that transfer the impulse (message) from the sense organs (body organs), as the name suggests, to the brain or spinal cord. E.g. Optic nerve: nerve connecting eye and brain, to transfer impulses from the eye to the brain, Auditory/Acoustic nerve: nerve connecting ear and brain, to transfer impulses from the ear to the brain.
Motor Nerves (contain only motor fibres): they are the nerves that transfer the impulse (message) from the brain or spinal cord to other body parts (muscles and glands). E.g. nerves from the brain to the muscles of the eyeballs, to transfer impulses from the brain to the eye.
Mixed/Association Nerves (contain both sensory and motor fibres): they perform the function of both sensory and motor nerves. They communicate between sensory and motor nerves. E.g. nerve that connects brain and tongue, where impulses transfer from the tongue to the brain, and from the brain to the tongue.

TYPE 2 (depending upon the place of origin of the nerves)

Cranial (brain) Nerves: they are the nerves that originate in the brain and reach the organs in the head region (nearby). There are 12 pairs of cranial nerves, which are 24 in number. It consists of both sensory and motor nerves.
Spinal (spinal cord) Nerves: they are the nerves that originate from the spinal cord and reach various body parts. There are 31 pairs of spinal nerves, which are 62 in number. It consists of both sensory and motor nerves.

NERVOUS SYSTEM IN HUMANS

Nervous system is the organ system that brings about coordination and integration of different body activities. E.g. coordination can be seen in this example: when we have food, our nose smells the food, our eyes help to locate the food, our hands bring the food to the mouth, the teeth and jaw muscles chew the food, saliva of mouth lubricates the food, and stomach digests the food.

Nervous system is a complex network of nerves that carry messages to and from the brain and spinal cord to various parts of the body. Here, the nerves carry out the task of a postman; bringing, sending and receiving messages one person to another person (from one body part to another part).

Nervous system → nerve/neuron, brain, spinal cord

THREE TYPES OF NERVOUS SYSTEMS

Central nervous system (CNS) (contains brain and spinal cord)
Peripheral nervous system (PNS) (contains cranial and spinal nerves only)
Autonomic nervous system (ANS)

CENTRAL NERVOUS SYSTEM (CNS)

The central nervous system contains brain and spinal cord. It is the main control centre of our body functions, responsible for all the processing of information, and responsible for processing of every sensation and thought we experience in our life.

BRAIN

Definition: Just as the Principal of the school is the main, who controls the working of the school; the CPU of a computer is the main control centre for the computer; the same way in the nervous system of humans, brain is the main control centre.

Location: Brain is located in the cranium of the skull, the area in the forehead and above. Cranium is the skull, i.e. the bone inside the head.

Weight: Average weight of brain in an adult is about 1200 to 1400 g (that is 2% of body weight).

Function: It controls each activity we do, thinking, feelings, movement and senses. It is also the site of intelligence. If the brain does not work, the person is like a living dead.

Membranes: Brain is enclosed in three membranes for protection, called the meninges. The fluid between these meninges is cerebrospinal fluid (CSF). Importance of cerebrospinal fluid → it nourishes the brain and protects it from shocks by absorbing them.

Three divisions of brain: cerebrum, cerebellum, medulla oblongata

PARAMETER	CEREBRUM	CEREBELLUM (little brain)	MEDULLA OBLONGATA
Location and Size	Bulk of the brain Uppermost and largest part	Small, egg-shaped lobe Located at the base of brain under cerebrum	Lowermost, located at the base of the skull
Structure	Highly convoluted (complex) with ridges and grooves, which increase the surface area to hold more neurons. Cerebrum is divided into → left and right cerebrum hemispheres with a deep furrow (trough) in between.	No convolutions, but has many furrows (trough)	Like a stem of brain, continues to become spinal cord in posterior (backward) region, although spinal cord is not the part of brain
Functions	1. Centre of memory and intelligence. 2. It controls mental activities, thinking and reasoning. 3. It is responsible for sensation of pain, temperature, touch, sight, sound, taste and smell.	1. It maintains balance of the body. 2. It coordinates movement of voluntary muscles.	1. It controls heartbeat, breathing, coughing, sneezing and other involuntary movements (therefore, it is 24/7 active, even when we sleep)

DID YOU KNOW?

Human brain takes up only 2% of human body weight, but consumes approximate 20% oxygen of your body through blood.
The left half of cerebrum (or left cerebrum hemisphere) controls right of your body, and the right cerebrum hemisphere controls the left of your body.

SPINAL CORD

Definition: Spinal cord is the continuation of the medulla oblongata at the base of the brain.

Location: It originates from the hole at the base of the skull that runs through the vertebral column.

Membranes: Just as the brain, spinal cord also has three meninges and cerebrospinal fluid (CSF) fluid between these meninges.

Cross-sectional view of spinal cord: If we cut the spinal cord in between, and then view the cross-section under microscope, we see that the cross-section has –

Two symmetrical halves like an H-shaped structure or butterfly.
The two halves are fused together to form a small canal in the centre, known as the central canal. The central canal also has cerebrospinal fluid.
The H-shaped area contains the cyton part of the neurons, and is called the grey matter. The area outside the H-shaped region contains the axon part (nerve fibres) of the neurons, and is called the white matter. (NOTE: The situation in the cross-section of brain reverses. In brain, the inner portion is white matter, and outer portion is grey matter.)

Function:

The spinal cord conducts the sensory impulses from skin and muscles to the brain, through sensory nerves.
The spinal cord also conducts the motor responses from brain to the skin and muscles, through motor nerves.

PERIPHERAL NERVOUS SYSTEM (PNS)

The system consists of two nerves: cranial and spinal nerves, coming up from the brain and spinal cord respectively.
Function of these nerves: to link the central nervous system (brain and spinal cord) with many different parts of the body
Fact: Sometimes these nerves are large and visible to the human eye.
This system is responsible for voluntary tasks.
It also consists of both sensory (afferent) and motor (efferent) nerves.

AUTONOMIC NERVOUS SYSTEM (ANS)

The system consists of two networks: sympathetic and parasympathetic system.
Function of the system: to control all the involuntary tasks of the body, e.g. heartbeat, muscle movement of stomach and intestines, etc. The medulla oblongata controls these involuntary tasks.

What is Motion in Physics?

October 7, 2023October 7, 2023

Hello friends,

In this post, we are going to explore ‘What is Motion in Physics?’. Motion is all about things moving or changing their position. Whether it’s a car zooming down the road or the planets in the sky, everything around us experiences motion in one way or another. Understanding motion helps us describe and predict how objects move, making it a fundamental concept in science and our daily lives. We are going to know about different types of motion, speed & velocity, and many other topics which is going to make our journey stimulating. So let’s dive into this matter.

What is Motion in Physics?

Motion is simply the act of something moving, like a bicycle rolling down the street or a bird flying through the sky. It’s what happens when an object changes its location or position over time. Motion is a fundamental concept in physics, helping us understand how things move and interact with one another in our world. Whether it’s a car racing on a track or a soccer ball being kicked into the goal, motion is all about how objects change their position, and it’s a crucial idea in the study of the physical world.

REST AND MOTION CONCEPT (What is Motion in Physics?)

Rest and motion are fundamental concepts in physics that describe the state of an object. When an object is at rest, it means it’s not moving; it’s staying still. Think of a parked car – it’s not going anywhere; it’s at rest. On the other hand, motion refers to when an object is moving from one place to another. When a car is driving down the road, it’s in motion because it’s changing its position.

TYPES OF MOTION IN PHYSICS

Distinct objects can possess several different style of manner to conduct their motion. An entity can acquire two or more types of motion at a particular time. Let us read further to get into the hidden depths of this topic.

1. TRANSLATORY MOTION

An object moving in such a manner that every part of that object moves the same distance in the same time is translatory motion. It has three types:

a) Rectilinear motion: the motion an object on a straight path is called rectilinear motion. For example: an apple falling from tree, a car moving on a straight road, a snooker ball being hit (billiards game).

b) Curvilinear motion: the motion of an object on a curved path is called curvilinear motion. For example: a ball being hit at an angle, a javelin throw, earth moving around sun.

c) Circular motion: It is a special case of curvilinear motion. The object moves on a closed curve path in which the distance of the object from the fixed point always remains the same. For example: a child sitting on a giant wheel/merry-go-round.

2. ROTATORY MOTION

An object rotating or spinning on its axis only (axis of rotation), it is called rotatory motion. Additionally, when an object is in rotatory motion, all the parts of the object do not move the same distance in the same time interval. Have this means that the part away from the axis moves greater distance in less time than the part near the axis.

For example: a 360º movable chair, a spinning top, wheel of a car, rotation of clock hands, spinning of potter’s wheel.

3. OSCILLATORY MOTION

The motion of the object falls under a to-and-fro pattern from its mean position (rest position). For example: swinging pendulum of wall clock, a child moving to-and-fro on a swing.

a) Vibratory motion: When only some part of an object moves to-and-fro, not the whole body, it is considered vibratory motion. Therefore, vibratory motion is called a special case of oscillatory motion. For example: prongs of a tuning fork, hitting/plucking strings of a guitar.

4. REPETITIVE MOTION

When an object repeats its motion in certain intervals of time, it is considered a repetitive motion. It may occur periodically (at regular intervals) or non-periodically (at any time).

a) Periodic motion: It is a type of repetitive motion which repeats itself at regular intervals of time (fixed). For example: earth taking a complete revolution of the sun , clock pendulum to-and-fro motion (oscillation).

b) Non-periodic motion: It is a type of repetitive motion which can occur at any point of time (not fixed). For example: motion of arms and legs while walking, breathing depends (motion of lungs changes), motion of a rolling ball, oscillating of tree branches.

5. RANDOM MOTION

When an object chooses a random or an irregular path for its motion, such that it repeatedly changes its direction or speed, it is listed under random motion. For example: a butterfly flying in an irregular path, a football/badminton player changing its speed and direction frequently, a dancer altering its speed and direction in order to change its steps.

Also read:

COMBINATION OR MULTIPLE MOTION

There can be an example of motion in daily life which falls under two or more categories of motion. Hence we can say that, an entity that possesses two or more types of motion is called a combination motion or multiple motion.

For example:

Drilling machine → rectilinear motion (it moves straight), rotatory motion (it rotates in its own axis).
Earth revolving around Sun → rotatory motion (earth moves on its axis), curvilinear motion (a curve forms when earth revolves around the Sun), periodic motion (revolution of earth occurs periodically).
Car wheels → rotatory motion (wheel moves on its axis), translatory motion (wheels can move on a straight or a curved path).
Bowling by a bowler → rotatory motion (ball is spinning when bowled), translatory motion (the ball reaches the batsman in straight or curve manner).
Swinging pendulum of wall clock → oscillatory motion (pendulum moves to-and-fro), repetitive motion (periodic motion: occurs at regular intervals).

ENERGIZER! (‘What is Motion in Physics?’)

Identify the types of motion and list them at the correct places in the table below.

Motion of your hands while running
Motion of a boy sitting on a merry-go-round
Motion of a train on a straight track
Movement of the lungs during breathing
Revolution of the earth around the sun
Motion of a butterfly
Motion of a horse pulling a cart on a straight road
Swinging pendulum of a wall clock
A flying bird
A swing in motion

Translatory	Rotatory	Oscillatory	Repetitive	Random
Motion of a boy sitting on a merry-go-round	Revolution of the earth around the sun	Motion of your hands while running	Motion of a boy sitting on a merry-go-round	Motion of your hands while running
Motion of a train on a straight track		Swinging pendulum of a wall clock	Movement of the lungs during breathing	Motion of a train on a straight track
Revolution of the earth around the sun		A swing in motion	Revolution of the earth around the sun	Motion of a butterfly
Motion of a horse pulling a cart on a straight road			Swinging pendulum of a wall clock	A flying bird

UNIFORM & NON-UNIFORM MOTION

Uniform Motion: The motion in which the object moves a straight path covering equal distances in equal time intervals is called a uniform motion. For example – a car that moves 80 km in 1 hour again moves 80 km in the second hour.

Non-uniform Motion: The motion in which the object moves unequal distances in equal time intervals is called a non-uniform motion. For example – a car that moves 50 km in first hour, 30 km in second hour and 60 km in third hour.

DISTANCE & DISPLACEMENT

The change in the position of an object can be stated as displacement.

What is DISPLACEMENT?

The shortest possible distance travelled by an object from its initial to final position following a straight path is called displacement. For example: a cat that travels A to B position and eventually turns to C. In such a case, the cat ultimately travels length AC, which is its displacement (shortest possible distance).

Distance and displacement are both distinct terms. Displacement is the shortest possible distance of an object as you have seen above with the help of the diagram, whereas distance is the actual length covered by an object (AB + BC) {long distance}.

What is DISTANCE?

The distance of an object is defined as the actual length travelled by an object (see the above diagram’s KEY).

Differentiate between DISPLACEMENT and DISTANCE.

Displacement

1) It is the shortest possible distance.

2) It is crucial to mention the directions (e.g. you cannot write CA, you have to show the direction so write AC)

Distance

1) It is a long distance as compared to displacement.

2) It is NOT necessary to mention the directions as it is the aggregate length.

What SIMILARITY do you observe in displacement and distance?

Both displacement and distance are expressed as lengths; therefore their SI units are metre (m).

Physical Quantities and Measurement II

October 7, 2023October 7, 2023

Hello friends,

Welcome to the exciting world of “Physical Quantities and Measurement II” These ideas are like the foundations of science, helping us measure and understand things like length, time, weight, and temperature. They make it easier for us to grasp how the physical world works and allow us to measure things accurately in science. So, let’s explore together how they’re essential in uncovering the secrets of the universe.

Measuring Length

In simple words, length means the distance of a straight line travelling through two points. To express distance through different methods, we use length, breadth (width), depth and height. The SI unit of length is metre and we denote it by an ‘m’.

To avoid confusion in the length of a metre throughout the world, the standard metre is put between two marks on a platinum-iridium bar kept at 0 degree located at the International Bureau of Weights and Measures in Sevres near Paris in France.

Every country owns a duplicate of the original metre for correct measurements of metre ruler which they manufacture. In India, the standard metre is there at the National Physical Laboratory in Delhi.

Common devices used to measure length

Some of the common devices used to measure length are –

1. Ruler –

Used for small measure.
Generally, available in 15 cm (6 inches) or 30 cm (12 inches).
A centimetre is further divided into 10 millimetres.

2. Metre Rod –

Has a fixed length of a metre.
It has 100 divisions, each of 1 cm (1m = 100cm).
A centimetre has 10 millimetres.
Generally, used by cloth merchants (tailors).

3. Measuring Tape –

Can contain more than one metres.
Used to measure long lengths (length of a field).
Have a flexible movement to measure curved objects too (size of a person’s chest, circumference of a tree trunk).

How to use a ruler correctly?

Reading correct measurement using a ruler plays a very important role. So, in order to take the correct measurement from the ruler, you will have to follow these certain steps.

• Avoid using the ends of a ruler – If you use your ruler in an improper way or you use it regularly, the edges and corners of your ruler get broken and it does not give that perfect line design on your notebook. So to prevent this problem, you should not put the left edge of the object (to measured) straight at the zero mark.

• Placing the ruler correctly – For a very correct measurement of your object, you should keep the ruler exactly parallel to the object and keep it as near as possible.

• Correct positioning of eyes – Correct positioning of eyes while measurement matters a lot. Whenever you are doing measurement with a ruler, you should always keep your eyes vertically and horizontally straight in line with the mark you are reading. Parallax error is the error which can be made while reading the measurement using a ruler.

Indirect Measurement of Length by Using a Ruler

To measure a curved or designed line using a ruler, you can do the following steps and you will definitely get the correct measurement.

Fetch a piece of thread.
Put the thread along the whole line and cut it wherever it ends.
Take a ruler and put the thread parallel to its marking.
Measure the length of the thread using the ruler.
The measured value of the curved line will be displayed.

Also read:

Measuring Mass

The amount of matter (solid, liquid, gas) present in the object is mass. The SI Unit of mass is ‘Kilogram (Kg)’. Generally, we don’t use the word mass in our daily life. Instead, we use the word weight. Suppose, if you purchase 3 kg of potatoes from a vegetable vendor then actually you are purchasing 3 kg mass of the potatoes.

The very common submultiples of mass are gram (g) and milligram (mg). We use these submultiples of mass to measure smaller quantities whereas, and quintal and metric ton to measure very big quantities.

Devices Used to Measure Mass

People have developed several devices to measure mass till date. Beam Balance/Grocer’s Balance, Electronic Weighing Machine and Physical Balance are some of the common devices for the same. Let’s move into deep detailed version of these devices.

1. Beam Balance (tarazu)

This is the simplest type of instrument which we can use to measure mass. Let’s see the structure of the beam balance:

We take the standard weights as a fixed quantity and the compare the unknown quantity with it.
Beam balance has a straight metal beam which is generally of iron.
Iron rod is supported with an iron loop in the centre.
There is a pointer between the iron loop.
We hang two identical pans from the two ends of the rod equally.
Both the pans are equal in their length and mass so that we don’t get a wrong weight.
Object (whose mass has to be calculated) is generally put on the right pan.
After that, we put the standard weights on the left pan.
Then, we put these fixed units in an increasing way on the pan till the metallic beam turns horizontal and the pointer becomes vertical.
At last, we take out the sum of the standard weights and calculate the mass of the object.

*One thing in notice that, when both the pans are empty, the metallic beam should be horizontal and the pointer should be vertical.

2. Common type of beam balance

Nowadays in the shops, there is a different type of beam balance (somewhat type of a digital machine, but not exactly digital) which is similar to the normal one. There are some changes as given in the points below-

No beam is present but a pointer is there.
The pointer moves whether right side or the left side in a rainbow shape according to the weight put on it.
So, if we compare this version with the traditional beam balance then we can say that if the pointer becomes vertical in this digital version then it means that both the pans have equal mass.

3. Electronic Weighing Machine

An electronic weighing machine is also a good device for measurement of mass. In this device, the measurement of mass doesn’t need to have the standard weights. Instead, it uses the LCD display panel right on its top which displays the mass of the object digitally.

4. Physical Balance

In the science laboratories or in a jewellery shop, the accuracy plays a very very important role. We can’t do these types of measurements using devices like beam balance. So, for that reason, we have a physical balance. A physical balance can do very sensitive calculations of mass measurement.

Measuring Time (Physical Quantities & Measurement II)

Time is very important for every task we do in our day to day life. The SI Unit of time is ‘second (s)’. Some other very common units of time that we use daily in our life is – minute (min), hour (h) and mean solar day.

Mean solar day is the time that the earth takes to complete one whole rotation in its own axis.

To measure the time of the day we use some units like- hour, minute and second. Commonly, we use the 12-hour clock system in which the day contains two periods of 12-hours.

What is a.m. and p.m.? – a.m. is the time from the midnight to the noon (12:00 in extreme morning till 12:00 in afternoon) and p.m. is the period from noon to again midnight (12:00 in afternoon till 12:00 extreme morning/night).

Devices for time measurement

To measure time, we can use many devices, like – nowadays, use of analogue and digital clocks, (in the past, use of sundial and sand clocks). Let’s go in more detail of these devices.

1. Sundial

The ancient people did not had very good facilities, thus they measured time by the movements of sun, moon, stars and other heavenly bodies. Later on, the ancient Greeks had prepared a device which was the sundial. The sundial was having the intelligence which says that when the position of the rod placed on it changes means that time has also passed and accordingly they used to measure time.

2. Sand Clock

The second ancient device developed was the sand clock. The intelligence put in this device was when the sand in the upper chamber of the device falls in the lower chamber, a fixed amount of time has passed.

3. Analogue Clock

The third device which is a very common device for time measurement in the modern world. It’s the analogue clock. These clocks are in a circular shape (and sometimes other shapes) with numbers from 1-12 written on it in the circular manner. It has two hands or maybe three hands at times which can rotate from the centre point of the circular dial. The three hands have a specific size and thickness to indicate a specific time duration, like the second hand is the longest and thinnest which indicates the seconds. A little shorter and little thicker hand reads the minutes whereas the shortest and the thickest hand indicates the hours and accordingly we note down the time of the analogue clock. The 12-hour time has 60 minutes and the 60 minute scale has 60 seconds, if any.

4. Digital Clock

The fourth and the last device is the digital clock which as the name suggests, displays the time digitally in number format. It shows the time in either ‘hours and minutes’ or in ‘minutes, hours and seconds’.

Physical Quantities & Measurement | Physics | KnockLedge

Time Intervals

Now, we’ve talked a lot about time, let’s try to know about the time intervals. We use time intervals to measure the time of an event having a fixed duration. To get an appropriate duration of the event, we can start or stop the stop watches and stop clocks at the beginning and at the end of a task.

24-hour Clock System

In the 24-hour clock system, we use the number of hours that have passed since midnight. We do not repeat the numbers two times as in the analogue system. The time from 00:00 till 12:00 indicates the time duration from midnight to afternoon whereas, time from 12:00 till 24:00 (or 00:00) indicates time duration from afternoon to midnight.

E.g. – 02:30 hours means 2:30 a.m., 17:00 hours means 5:00 p.m.

(V.I.P Formula: 17:00 – 12:00 = 5:00).

Public facilities like railways and airlines have a non-stop 24-hour duty and thus they use the 24-hour clock system.

Main Features

The use of a.m. and p.m. in the timings is not there to avoid confusion.
We show the time by displaying 4 specific digits. The first two digits show the number of hours and the next two digits show the number of minutes.
We divide the hours and minutes by a colon (:) in 2 pairs of 2 digits.
Time continuously passes one number by number without any repetition.
The time 00:00 and 24:00 are both same.

Also read:

What are Algorithms and Flowcharts?

October 7, 2023October 7, 2023

Hello Friends,

Welcome to the world of problem-solving with Algorithms and Flowcharts! These two essential tools are like a roadmap for computers, guiding them in making decisions and solving puzzles step by step. In this article, we’ll explore what Algorithms and Flowcharts are all about and how they help simplify complex tasks, making them accessible to both machines and humans. So, let’s dive into the fascinating world of Algorithms and Flowcharts to unravel their significance in problem-solving.

ALGORITHMS

WHAT ARE ALGORITHMS?

It is a series of instructions to perform a task.
It is the step-by-step solution (process/procedure).

How to solve any problem?

Know the problem
Analyse the problem
Find the best solution, i.e. the easiest solution having less steps, precise and unique.

Finally, algorithm is a step-by-step process to obtain a solution for a specific task when executed. The most efficient algorithm is chosen based on the solution, the solving time and the amount of space used by an algorithm.

Advantages of algorithm

Doesn’t use programming terminology, so easy to understand
If any error, it can easily be identified and solved
Independent of any programming language, and everyone is eligible to make an algorithm

Disadvantages of algorithm

Solutions of complex problems cannot be made an algorithm easily
Time consuming
Difficult to explain loop concepts (repetition)

Criteria of algorithm

The steps should be in sequence.
Steps can include mathematical expressions.
Variable can be used (to store values of input, intermediate and final result).
The words ‘read’ and ‘print’ are ideally used in place of input and output.
Any step can be repeated any number of times; or the number of repetitions can be specified to reduce the number of steps.
Decision is made using a condition, using if-else statements.
Output can be numerical, Boolean, a line of text, etc.
The best solution must be selected from the number of solutions to a given problem, and should be stated as an algorithm.

Steps to develop an algorithm

Problem description – The problem to be solved must be easy to understand.
Analyse the problem – Decide the type of input, output and problem by listing the characteristics (decide whether: the solution is numerical, etc; the solution is a single value or multiple value; the problem requires a formula or not).
Develop algorithm (process of solving) – Write the step-by-step solution.
Test the algorithm – check each step and the final output and determine it has performed the intended operation.
Review the algorithm – checking for changes, more simplifications, solves problem based on the analysed problem, etc.

CHARACTERISTICS OF ALGORITHMS – IODFU

I – Input – There can be zero or more quantities as input.
O – Output – There should be at least one output.
D – Definiteness – Each instruction should be clear and easy to understand.
F – Finiteness – There should be finite number of steps producing an output.
U – Unique – Each step should produce a unique result depending upon the input and the previous steps.

Pseudocode: a notation similar to any programming language but does not involve the complicated syntax of that programming language. Instead, structural conventions for the same are used (no machine-readable code, therefore easy to write and understand).

Also read:

EXAMPLES OF ALGORITHM

Write an algorithm to prepare maggi.

1. Take maggi, bowl, water and salt.

2. Take water in a bowl, add maggi and boil it for 2-5 minutes.

3. Add spices or vegetables according to your taste.

4. Cook it for 4-5 minutes.

5. Your maggi is ready!

Write an algorithm to add 2 numbers.

1. Take two numbers (a, b).

2. Calculate the sum (c = a + b).

3. Print the sum (c).

Write an algorithm to calculate the simple interest.

1. Input Principal, Rate and Time (P, R, T).

2. Calculate the simple interest ·(SI = (P*R*T)/100).

3. Print the Simple Interest (SI).

Write an algorithm to check whether a number is positive on negative.

1. Input a number (n).

2. Check if, n>0
If true, print “Positive no.” If false, print “Negative no.”

3. If n=0, print “zero”.

Write an algorithm to calculate the average of 3 numbers.

1. Input three numbers (a, b, c).

2. Calculate the average (Avg = (a+b+c)/3).

3. Print the average (Avg).

Write an algorithm to calculate and print the area and circumference of a circle.

1. Input the radius of a circle.

2. Calculate the area of the circle (A = 3.14*r*r).

3. Print Area (A).

4. Calculate the circumference of a circle (C = 2* 3.14* r).

5. Print the circumference (C).

Write an algorithm to input age and check whether the person is eligible to vote or not.

1. Input the аgе (a).

2. Check if, a>=18
If true, print “You can vote.” If false, print “You can not vote.”

Write an algorithm to input a number and check whether it is even or odd.

1. Input a number (n).

2. Check if, n%2=0
If true, print “Even no.” If false, print “Odd no.”

Write an algorithm to input three numbers and print the largest one.

1. Input three numbers (a, b, c).

2. Check if, a>b and a>c

If true, print a..
If false, go to step 3.

3. Check if, b>c and b>a.

If true, print b.
If false, print c.

Write an algorithm to check whether a number is Buzz or not.

INFO: BUZZ No. ends with 7, e.g. 797 or BUZZ no is divisible by 7, e.g. 70.

1. Read a number (n).

2. Check if, n%7=0 or n%10=7

3. If true, print n is a buzz no. If false, print n is not a buzz no.

State Legislature and Parliament

October 7, 2023October 6, 2023

Hello friends, In India’s democracy, the State Legislature and Parliament are like important puzzle pieces. They help make rules and laws that affect many people. The State Legislature takes care …

HISTORY OF COMPUTERS | KnockLedge

May 19, 2024December 17, 2022

History of Computers | KnockLedge Major Milestones | People Responsible for the development Hello Friends, In this post of history of computers | KnockLedge we get to know that the …

Simple Machines | KnockLedge

June 2, 2022May 24, 2022

Dear readers, I am here with another exciting n’ informative article. In this post, we have revealed all those contents and common questions that click your mind while studying this …

Inside Computers | Hardware and Operating Systems

May 24, 2022May 13, 2022

Dear readers, I am here with another exciting n’ informative article. In this post, we have revealed all those contents and common questions that click your mind while studying this …

The Mesopotamian Civilization | History by KnockLedge

October 7, 2023October 19, 2021

Hello friends,

In this post, The Mesopotamian Civilization | History by KnockLedge, we are here with another exciting n’ informative article. In this post, we have revealed all those contents and common questions that click your mind while studying this topic, as mentioned below in the table of contents. Please read the article to get substantial knowledge about the topic. THANK YOU!

What is a Civilization?

Civilization word has derived from the Latin word ‘civitas’ which means city. A civilization must have the features mentioned below-

1. People live in towns and cities.

2. Trading is performed with other different cities.

3. A language is formed which helps in transfer of knowledge.

4. Social and economic factors between two persons or some groups of people exist. Some groups are very strong and some have no power.

5. A government is formed with law and order to avoid the disputes between people.

6. Many religions exist with there own culture and beliefs.

The early river valley civilizations from where human life started were the four places mentioned below-

1. Mesopotamia, between Tigris and Euphrates (Iraq).

2. China, Hwang-Ho valley.

3. Egypt, Nile valley.

4. Harappa, Indus valley (India).

Approximately 2500 BCE, these four cities (Mesopotamia, Egypt, India, China) were introduced as the centers of civilization. These cities had some features in common whereas some unique features.

The early civilizations came up near rivers due to the following reasons –

a) The water of the river was used by the people for drinking and other purposes.

b) The running water became a means of transport for trading profitable to the people.

c) As the land near the river was fertile, people could grow crops and irrigate.

The Mesopotamian Civilization | History by KnockLedge

Mesopotamia is a city between the river Tigris and Euphrates. It is also called the ‘cradle of civilization’ as the birth of civilization started from here. It has four cities namely: Sumer, Akkad, Babylonia and Assyria.

Sources

We collect the information about Mesopotamia through the sources present over there. Some of them are the

archaeological sources such as the ziggurat in Ur, the seals and also the literary sources like the ‘Epic of Gilgamesh’.

Origin (Beginning or Birth)

Around the third millennium BCE (3000 years), a civilization called Sumer was developed which was the world’s first civilization. Birth of humans nearly started in this location of Mesopotamia.

Mesopotamian Cities

Sumer is divided into 5 cities: Eridu, Kish, Uruk, Ur, Lagash.

The archaeologists dugged and found these cities later. Ur is the biggest city and the major port for trading amongst these 5 cities. There is a Great Ziggurat in Ur dedicated to Nanna – the moon god. Then, Ur had 3 categories named, the sacred area, the walled city and the outer town.

(1) Sacred Area

Sacred area is the most pure and patron area of Ur. There was a tower ‘the ziggurat’, on top of which a temple of the patron god was present. The priests did all the prayers and worshippings. The sacred area also consisted of the offices and storehouses.

(2 & 3) Walled City & Outer Town

The walled city and the outer town was the residential areas which consisted mud-brick houses of different sizes that have been later on found by research. Each house had a central courtyard with rooms surrounding it.

Also read:

Social Classes

The king and his royal family were the most powerful in the social ladder. He performed many religious rites and sacrifices being the head priest. Then came the priests, high officials and scribes (writers). Scribes were the special people at that time because, everybody didn’t knew how to write. Farmers, traders and artisans were next in importance. The slaves were at the bottom position of the social ladder.

If we talk about family, so at that time the father was the head of the family. Women were not treated equal to men. Boys were sent to the school whereas girls were told about cooking, spinning and other household work. Some girls were also taught reading and writing.

Religion (way of living/habits)

The Mesopotamians believed in many different forces of nature like: the Sun God as they gave sunlight for survival and the Water God for drinking. They also believed in many gods. Each city had its own god. On the top of the ziggurats, all the statues of gods were located, priests did the ceremonies and people worshipped the god.

Through the excavated (dugged) evidences, it is proved that life after death was a belief of the Mesopotamians. Its proved by discovering the graves containing daily articles and other useful things and utensils which the dead person may need in his afterlife.

Occupations (Profession)

Most of the Mesopotamians were farmers. They grew crops like: wheat, barley, corn, dates, vegetables and fruits. Agriculture, the work of farmers, started in the 3rd period of Stone Age which was the Neolithic or the New Stone Age. Its time period was from about 8000 BCE till 4000 BCE (4000 years). Irrigation through the water of rivers made it easy for farmers to increase crop production. Among farmers, there were different craftsmen of different types like: metalworkers of blacksmiths and goldsmiths, potters, weavers, sculptors, glass-makers and many more.

Trade and Commerce

The people of Mesopotamia did trading in many goods. They imported raw materials, converted them into finished products then did trading and sold them in other cities and their home. Strict supervision took place for the quality of the products. People wrote the records of trade on clay tablets. Instead of bills in today’s world, Mesopotamians used seals to confirm that the product is there’s. The discovery of these seals was in the Indus valley cities which proves that the Mesopotamian products had a trade with India, and the archaeologists found the seals of the Indus valley cities in Mesopotamia.

Architecture

Stones were not easily available at that time in Mesopotamia, so the Mesopotamians used baked bricks to make buildings and temples. The reason why Mesopotamians used only baked bricks was that as the urban pot keeps the water inside cool, the houses made up of baked bricks were cool from inside. Some architectural forms, which were one of the greatest contributions of Mesopotamians, were some of these: arch, column, dome and vault. These architectural forms were used in the buildings and houses.

Mesopotamians made many ziggurats. There were many storeys (floors) in the buildings which were high and had decorations with marble, tiles and precious stones. The drains of baked bricks were put on the side of the ziggurats like a wall so that the rainwater can be carried away from the ziggurats.

The Hanging Gardens of Babylon, one of the seven wonders of the world. King Nebuchadnezzar created it for his wife as she missed the hilly landscape of her home.

Educational Sciences (Qualifications)

The Mesopotamians excelled in mathematics and astronomy. We count by tens but they counted by sixties. They divided an hour into 60 minutes and a minute into 60 seconds. A year had 12 months and a month consisted of 30 days. A day had 12 hours. In astronomy, Mesopotamians gave specific names to the planets and stars. They could also predict eclipses like solar and lunar eclipse.

Script (Way of Writing)

When the people of Mesopotamia and other people of other cities began to trade, the requirement of writing the records became very essential. So, keeping this in mind, the Sumerians invented the word ‘writing’ approximately 5500 years ago. This system of writing is ‘cuneiform’ by Mesopotamians. It was a wedge-shaped script. They wrote from right to left with a pen made up of reed of bone.

People did all the writing work on clay tablets and after writing they baked them so that it sticks over there and no one can disturb it. Each tablet was like a page of a book. Archaeologists found many tablets amongst which, one of the most famous tales are about the legendary hero, ‘Gilgamesh’.

Hammurabi’s Code of Law

Hammurabi was a king of Babylon who wrote all the 282 laws on a huge stone slab which the archaeologists found by excavating in Mesopotamia. Some of these rules were about: trade and commerce, family, civil and criminal disputes. The punishment depends upon the severity of the offence, the circumstances of the offence and the status of the offence.

Decline

Being the earliest and the long lasting river valley civilization of the world, Mesopotamian Civilization fell into decline. Although, the buildings and other strides made by the Mesopotamians in architecture, sciences and script has made the history of humankind.

Star Facts 💫

The early river valley civilizations used bronze (copper) to make tools and implements. That’s why they are also the ‘Bronze Age Civilizations’.
People believe that Marduk, the Babylonian god, created the world after defeating the monster.
Enheduanna was a priestess of Akkad. But she is perhaps also the world’s first writer and poet.
People believe that Marduk, the Babylonian god, created the world after defeating the monster.

Physical Quantities & Measurement | Physics | KnockLedge

October 7, 2023August 7, 2021

Physical Quantities & Measurement | Physics | KnockLedge Hello friends, Welcome to the world of science and understanding! We’re about to explore “Physical Quantities & Measurement | Physics | KnockLedge.” …