Category: Physics Notes PPT

Have you ever wondered how radio plays a channel of a selected frequency or why the voice of an opera singer shatters a wine glass? Well, it all happens due to the phenomenon of forced oscillation and resonance. Under normal conditions, when there is no external damping or driving force, a system will generally oscillate at its natural frequency. But, when a driving force is applied to the system periodically, some energy is put into the system at a frequency different from the system’s natural frequency of oscillation. The system will now be “forced” to vibrate with the frequency of the external periodic force, giving rise to forced oscillations. The difference between the natural frequency of the system and that of the driving force will determine the amplitude of the forced vibrations; a larger frequency difference will result in a smaller amplitude.

Oscillation can be described as the repetitive motion of an object between two different points or states. The word Oscillation is derived from the Latin term Oscillate which means “to swing”. In simple words, when a body is in to and fro motion with respect to a central axis or point, it is termed as oscillation. You can understand the concept of oscillation very easily by observing the motion of a pendulum. The vibration of the string in instruments like the guitar is also an example of oscillation.

How are Free and Forced Oscillations Different?

Free oscillations differ from forced oscillations in the following respects:

• Free oscillations or vibrations occur in the absence of an external force. But forced oscillations take place under the influence of an external driving force.

• While the frequency of free oscillations depends solely on the source of vibrations, the frequency of forced oscillations is affected by the source of vibration and the frequency of the applied driving force.

• In the case of free oscillations, the frequency of vibration remains constant throughout. However, the frequency of forced oscillations can be altered by changing the frequency of the driving force.

• The amplitude of the vibrations remains constant for free oscillations. But in the case of forced oscillations, the amplitude may increase, decrease, or remain constant.

What is Resonance? 

So what gives rise to resonance oscillation? Resonance is a particular case of forced oscillation. When the frequency difference between the system and that of the external force is minimal, the resultant amplitude of the forced oscillations will be enormous. However, when the two frequencies match or become the same, resonance occurs. Thus, at resonance, the amplitude of forced oscillation is maximal, and the natural oscillating frequency of the system is equal to the frequency of the periodic driving force. 

The following diagram illustrates forced oscillations and resonance:

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Displacement – Time Graphs for Different Oscillations

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Types of Resonance

Resonance can be of the following types:

• Mechanical Resonance: A mechanical system tends to absorb more energy when the natural frequency of vibration of the system matches the frequency of its oscillations. The phenomenon of mechanical resonance may result in extreme vibrations leading to wild swaying motions and often, the collapse of structures like buildings, bridges, trains, and aircraft.

• Acoustic Resonance: The mechanical vibrations that occur in the audible range of the human ear constitute acoustic resonance. It is a branch of mechanical resonance that deals with the vibrations produced within the frequency range of 20 Hz to 20 kHz. Acoustic resonance is a crucial factor for building instruments that use resonators, like the body and strings of a violin, the length of a fluted tube, or the tension of a drum membrane.

• Electrical Resonance: The phenomenon of electrical resonance is observed in electrical circuits. It is used to transmit and receive wireless communication as in cell phones, television, and radio.

• Optical Resonance: Optical resonators or resonant optical cavity is widely used in lasers. It comprises an arrangement of optical components that enables the circulation of a beam of light in a closed path. 

• Orbital Resonance: This is a concept related to celestial mechanics. In the case of orbital resonance, two orbiting bodies mutually exert a periodic and regular gravitational force. As a result, the mutual gravitational effect of the bodies is greatly enhanced.

• Atomic Resonance: The concept of resonance in particle physics pertains to particular quantum mechanical properties observed in an atomic nucleus under the influence of an externally applied magnetic field. Nuclear Magnetic Resonance (NMR) finds application in several scientific techniques like spectroscopy and Magnetic Resonance Imaging (MRI); NMR spectroscopy can be used to study molecules, crystals, and non-crystals, whereas MRI is used in medical imaging procedures.

We have heard of waves in our everyday lives like water waves and sound waves. On this page, we will learn what a Wave is and its primary characteristics.

We can define a Wave as a continuous and recurring disturbance of a medium.

In our world, we observe various phenomena like throwing a stone in the water and seeing ripples, plucking the strings of a guitar, an oscillating string of thread, earthquake waves, and tsunami waves.

A wave needs a medium to propagate. Without this medium, a wave would not be able to travel. The medium itself does not move, but if we look at it as an interlinked series of several particles, we can say that when a wave interacts with one particle. It allows the wave to pass through the disturbance to the interacting particles. For example, a spring coil has a medium of a metal spring, just like in the case of a sound wave, the air through which that wave travels is its medium

Waves only transport energy and do not matter. Suppose there is a disturbance in the medium which is transporting the wave. In that case, the particles temporarily become displaced from their position and only get back to their original position if a restoring force brings them back there.

Types of Waves

We can categorize waves into three types. This depends on how the particles are directed and propagated through that wave:

Transverse Wave: When the particle movement is perpendicular to the energy’s direction of the movement in the medium. Example: Wave of a rope.

Longitudinal Wave: When the particle movement is parallel to the energy’s direction of the movement in the medium. Example: Sound moving through the air and forming a pattern.

Surface Waves: When the particle movement occurs along the energy’s direction of the movement in the medium in a circular motion. Example: Seismic Waves, Electromagnetic Waves

Before getting into Frequency and Wavelength, let us know some more essential terms.

Crest: A crest is the highest point of the wave.

Trough: The trough is the lowest point in a wave.

Wave Height: Wave Height is the vertical distance we can observe between the crest and the trough near it.

Amplitude: An amplitude is half of the height of a wave. We can define amplitude as the measure of disturbance in a substance from the equilibrium position.

Frequency

The term frequency means the number of times a particle vibrates when the sound wave passes through a medium. We measure frequency as the total number of vibrations in a unit of time. 

For example, suppose a longitude wave vibrates about 10000 vibrations in 5 seconds. In that case, its frequency will be 2000 vibrations per second. The unit for frequency is Hertz.

1 Hertz = 1 Vibration/Second

When a sound wave travels through a medium, each particle in that medium vibrates at the same frequency. This happens because each particle vibrates due to its neighboring particle. Since only energy gets transferred, they vibrate at the same frequency as the previous particles.

The speed of a wave also depends on the medium through which it travels. For example, the speed of light is lesser in a medium when it travels through a vacuum instead of air. This also tells us that this same frequency corresponds to a shorter wavelength in any medium than the vacuum.

Wavelength

Wavelength can be defined as the distance between the two consecutive crests or troughs in a curve. In a high-frequency wave, the distance between the crests and troughs is less than in a low-frequency wave and vice-versa.

Frequency is inversely related to Wavelength.

We measure Wavelength in nanometers, denoting it by the Greek Symbol Lambda (λ).

We more commonly apply the concept of a wavelength to waves of a sinusoidal pattern.

Sinusoidal Pattern is also commonly known as a Sine Wave, which describes a smooth periodic oscillation. A Sine wave is continuous, and we name it after the sine function.

In a linear system, we observe that the sinusoid is one of the simplest forms without disturbing its shape.

Mediums like Light, Water, and Sound all travel as waves. The equation we use to donate their motion is the same, which is:

F = c/λ

Here, we see that F is the wave’s frequency, whereas c is the speed, and Lambda is the Wavelength.

We can find Electromagnetic Waves in mediums like Light. We can describe them by their frequency, wavelengths, and energy. These three properties of the electromagnetic wave relate to Light and one another. 

All lights travel at the same speed regardless of their color. However, if their wavelengths are different, they can turn into different colors. We can often see these lights separate into different colors in a prism. Red has the lowest frequency and the longest Wavelength in that spectrum that we produce. In contrast, on the other end, violet has the highest frequency but the lowest Wavelength.

This tells us that the higher the wave’s energy, the higher is the frequency and the longest Wavelength. In the same way, colors of a short wavelength also have a high frequency. They are more vibrant than the colors with a longer wavelength and lower frequency.

Gauss rifle or Coilgun or Gaussian gun is a type of mass driver that consists of one or more coils being used as electromagnets in the configuration of a linear motor that accelerates a ferromagnetic or conducts a projectile to high velocity. Coils and the gun barrels are arranged around a common axis in almost all coilgun configurations. Coilgun is not a rifle as the barrel is the smooth article. The name “Gauss” referred to Carl Friedrich Gauss. Carl Friedrich Gauss invented and explained the mathematical descriptions for the magnetic-effect that had been used by magnetic- accelerator cannons.

The mass driver is the kind of a coilgun that magnetically accelerates a package having a magnetizable holder having a payload. When its payload has been accelerated, the two separated, and the holder is slowed and recycled for another payload.

Coilguns typically have one or more coils arranged in a pipe called a barrel, therefore the path of the accelerating- projectile is kept along the central axis of the coils. These coils are being switched on and off in an accurately timed sequence, causing the projectile to be quickly accelerated along the tube barrel through magnetic-forces.

Coilguns are different from railguns as they accelerate at right angles to the central axis of the current loop being formed. Also, railguns normally require the use of sliding contacts for passing a large current from the projectile, but the coilguns do not necessarily need sliding-contacts.

History

Norwegian scientist Kristian Birkeland invented the first Coilgun from the university of Kristiana in 1900. In his experiments, Birkeland accelerated a 500 gm projectile with 50 m/s speed (110 mph, 180 km/h, 160 ft/s).

In 1933, Texan inventor Virgil Rigsby, Texan inventor developed a stationary coilgun which was designed as a machine gun in 1933. A large electric motor and generator were used to supply the power in it.

There are mainly two types of setups in Coilgun, i.e. single-stage and multistage. A single-stage coilgun uses only one electromagnet to propel it from the projectile while A multistage coilgun has many electromagnets in succession that progressively increase the projectile-speed.

Ferromagnetic Projectiles

A single-stage coilgun can be formed for ferromagnetic projectiles, by the coil of wire, and an electromagnet along with a ferromagnetic projectile kept at one of its ends. This Coilgun is formed like the solenoid which is used in an electromechanical relay. A large current is applied through the coil of wire, and a strong magnetic field generated that pulls a projectile towards the centre of the coil.

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An illustration of a solenoid

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A single-stage coilgun after electromagnets were used for repeating the same process to progressively accelerate the projectile in a multistage-design.

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A simplified diagram of a multistage coilgun with three coils, a barrel and a ferromagnetic projectiles

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A multistage coilgun

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A simple electromagnet consisting of a coil of wire wrapped around an iron core. 

We use a diode to protect the polarity sensitive components from the damage due to inverse-polarity of the voltage after turning-off the coil.

Non-Ferromagnetic Projectiles

Some of the designs for Gauss rifle consist of non-ferromagnetic projectiles, which are made of materials like Aluminium or Copper. In this case, the armature of the projectile acts as an electromagnet with the internal current induced by some pulses of the acceleration coils. Quench gun is an example of Non-ferromagnetic projectiles. It is prepared by successive quenching of adjacent-coaxial conducting coils. It forms a gun barrel and generates a magnetic field gradient to get more desirable speed.

Switching

There is one main obstacle for the coilgun design, which is switching the power through the coils. For switching several common solutions are being used, however, the simplest and probably the least effective one is the spark gap that releases the stored-energy by the coil when the voltage reaches a certain threshold value.

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A spark gap

The second or better option is to use solid-state switches; these include IGBT (Insulated-gate bipolar transistor) or power MOSFET and SCR.

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Silicon controlled rectifier

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MOSFET, showing gate (G), body (B), source (S) and drain (D) terminals.

A quick-and-dirty method for switching is when we use the flash-tube itself as the switch. Prepared by wiring it in series with the coil, it can silently and non-destructively permits more current to pass through in the coil so a large amount of the energy will dissipate as heat and light, and, as the tube being a spark-gap, the tube stops conducting when the voltage across it will drop sufficiently, leaving some charge remaining on the capacitor.

However, in order to reduce the component size, weight, durability, and most importantly, the cost, the magnetic circuit has to be optimized to deliver maximum energy to the projectile for given energy input. It has been addressed to some extent by the use of back iron and end iron.

How to Prepare a Gauss-Rifle?

For making a Gauss Rifle, i.e. a steel ball rolls to a magnetic taped plastic-rail. When the magnet gets hit by the steel ball, another one shoots on the opposite side at a quite higher speed. For the preparation, we require some simple materials as given below:

1. Wooden Ruler

2. Two dowels

3. Copper pipes

4. Clear adhesive tape

5. Glue

6. Strong cylindrical magnets

7. Nine steel balls

Preparation

(a) We place the first magnet at the 2.5-inch mark on the wooden-ruler.

(b) Fix the ruler on the table with the help of a tape so that magnets attach to prevent jumping.

(c) Then we place four magnets on the ruler at the 2.5-inch gap between them.

(d) Place two steel balls on the right-hand side of each magnet, And ensure that the ball doesn’t roll down from the wooden ruler.

(e) Now, we have to fire, so set the ball on the extreme left magnet then push-roll to the magnet.

(f) While the gauss rifle will fire the ball on the right-shoots away from the gun to hit the target with sustainable required force.

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Gauss Rifle

Observation

When we release the first ball to the extreme left magnet, it will hit it with a sufficient amount of force and produces kinetic energy. This energy carried from the ball is transferred to the magnet and then the ball on the right releases. Then the third ball will move with kinetic energy and repeats the process until the last ball shoots with the greater force.

The Gravitational constant is introduced in physics to determine the gravitational force of attraction. The Universal law of gravitation is an important discovery in the field of physics. It gives an insight into the relationship between mass and force. The law of gravitation states that- every object in the universe attracts every other object such that the force exerted will be proportional to the product of the masses and inversely proportional to the square of the distance between them. 

The proportionality constant incorporated in the universal law of gravitation is known as the universal gravitational constant. The universal gravitational constant is numerically equal to the Force of attraction between two unit masses placed at a unit distance apart. The Gravitational constant plays an important role in determining the force between two objects with maximum distance. The gravitational constant balances the gravitational force without violating the laws of physics.

What is the Gravitational Constant Universal Law of Gravitation?

Before understanding what is the gravitational constant in the universal law of gravitation, let us have a look into the mathematical part of the gravitation law in detail. As we know that universal gravitation law states that the force between two point mass objects is directly proportional to the product of masses and inversely proportional to the distance between them. 

Therefore, Newton’s law of gravitation says that,

• The magnitude of the force acting between two point masses is directly proportional to the product of their masses.

• The magnitude of the force acting between two point masses decreases rapidly as distance increases.

Mathematically we write,

Consider two objects having masses m₁ and m₂ separated by a distance r, as shown in the figure. 

According to the statement of the law of gravitation,

The magnitude of the force acting on the body is directly proportional to the product of the masses of interacting bodies, then we get:

⇒ F ∝ m₁ m₂ …….(1)

Also, the magnitude of the force acting between two objects is changing rapidly with increasing distance, then Newton gave a standard value that, the force is inversely proportional to the square of the distance between them, i.e.,

[Rightarrow Falpha frac{1}{r^{2}}]……….(2)

Then, he generalized both statements by combining (1) and (2) :

[Rightarrow Falpha frac{m_{1}m_{2}}{r^{2}}]………(3)

Where,

m₁ – The mass of the first object

m₂ – The mass of the second object

r – The distance between two objects

Equation (3) is re-arranged by removing proportionality and replacing it with a constant known as gravitational constant.

[Rightarrow F=Gfrac{m_{1}m_{2}}{r^{2}}]……….(4)

Where,

m₁ – The mass of the first object

m₂ – The mass of the second object

r – The distance between two objects

G – The universal Gravitational constant

The value of the proportionality constant that is the value of the universal gravitation constant is found to be G = 6.673 x 10^-11Nm²/kg².

Equation (4) is known as the mathematical form of Newton’s law of gravitation or the law of gravitational force. From equation (4) we find that the force acting on each other will be directly proportional to the product of point masses and inversely proportional square of the distance between them. It is also known as the inverse square law. 

The gravitational force acting between two objects is only due to their masses. The gravitational force is one of the four basic forces of physics. The gravitational force is valid throughout the universe. For significant gravitational force, one among the two objects must be larger than the other.  

Since we have understood what is the gravitational constant universal law of gravitation, let us look at the universal gravitational constant.

Define Universal Gravitational Constant

The gravitational constant can be defined as the constant relating the force exerted on the objects to the mass and distance between the objects. The gravitational constant is equal to the numerical value of the attracting force when two unit masses are separated by a unit distance. 

The value of the universal gravitation constant is found to be G=6.673 x 10^-11Nm²/kg². We define universal gravitational constant as a constant of proportionality to balance the equation. The dimension of the gravitational constant is [M^-1L³T^-2].SI unit of G is given by, Nm²kg^-2.

The gravitational constant serves a very specific purpose in the law of universal gravitation, it is not just a number but also has units. Let us have a look at the units of the gravitational constant. 

From the law of universal gravitation we have,

[Rightarrow F=Gfrac{m_{1}m_{2}}{r^{2}}]

Where,

m₁ – The mass of the first object

m₂ – The mass of the second object

r – The distance between two objects

G – The universal Gravitational constant

We know that force is measured in Newton’s and masses measured in the kilograms and distance in meters. Then the units on the right-hand side are not equal to the left-hand side, we need something that will balance, thus the Gravitational constant is introduced. Then from our analysis the possible unit of the universal gravitational constant is,

⇒ G=Nm²/kg²

Therefore, the unit of gravitational constant is Nm²/kg².

Did You Know

What is interesting here is that, albeit it’s Newton’s Universal Law of Gravitation, the worth of G wasn’t given by him. This was calculated by Cavendish in 1
798 through a series of experiments and observations. It is hypothesized the influence of the earth’s core on the experiments alters its rotational inertia due to which the worth of G given isn’t always constant throughout the globe.

Another theory regarding the universal gravitational constant ( it is also referred to as Big G) is that, if it is true that the universe is expanding since the Big Bang, then the worth of G will keep decreasing.

The universal gravitational constant is employed in Newton’s Universal Law of Gravitation, Einstein’s General Theory of Relativity and also Kepler’s Third Law of Planetary Motion, to calculate the period of time of a planet to finish one full revolution in its orbit.

Vehicles are widely used means of transport to move from one place to another. Nowadays, every family can possess at least two-wheelers. Just imagine how the vehicles are moving? What is the energy used in it? What is the process that has undergone? A heat engine is the only answer to all those questions.

What is the Heat Engine?

A heat engine is a device used to convert heat energy into mechanical work which is useful for people. It uses a simple apparatus to perform the procedure. The heat engine processes several advantages along with few limitations.

Classification of Heat Engine

We have five different types of heat engines. There are two types of well-known and widely used heat engines among the five. The characterization has taken place based on the principle which is used to convert heat energy into mechanical work. So the types of heat engines are as follows:

What is the function of a Heat Engine?

The primary function of any heat engine is to convert the available heat energy into useful mechanical work. It undergoes various procedures to convert the same.

Definition of the efficiency of the Heat Engine

Generally, we know that efficiency is capability. However, here the efficiency of a heat engine is the ratio of  difference between the hot source and sink to the temperature of the hot source. It can also be termed as the thermal efficiency of the heat engine. The maximum efficiency of a heat engine is possible if there is a  highest difference between hot and cold reservoirs. Efficiency does not have any unit.

The thermal efficiency may vary from one heat engine to another heat engine. To understand more about this, let’s take the reliable heat engines and their efficiencies. The efficiencies of various heat engines are as follows:

It is just 3% efficient for ocean thermal energy conservation.

Automotive gasoline engines are nearly 25% efficient.

Similarly, coal-fired power stations have 49% efficiency.

It is around 60% efficient for the combined cycle gas turbine.

The Efficiency of a Heat Engine Formula

As the efficiency of the heat engine is a fraction of heat and the obtained useful work, it can be expressed using a formula and a symbol. The efficiency of heat energy formula is,

η = [frac{W}{Q_{H}}]

Where,

η = Thermal efficiency.

W = Useful work obtained.

Q_H  =  Given amount of heat energy.

This is known as the heat engine formula.

According to the second law of thermodynamics, it is impossible to get 100 percent of the thermal efficiency. It always ranges between 30% and 60% of thermal efficiency because of the environmental changes and other factors. We can also consider the work attained to be the difference between the initially absorbed amount of heat and the  heat released. It can be expressed as

(η) = [frac{left [ Q_{1} -Q_{2}right ]}{Q_{1}}]

The heat engine concept was first introduced and discovered by a French Physicist Carnot in 1824. The Carnot engine is the ideal heat engine.  As it is the most efficient heat engine, its efficiency is [frac{left [ T_{1}-T_{2} right ]}{T_{1}}]. It can be measured for every Carnot cycle.

From the formula and diagram, we can understand that the efficiency of an ideal heat engine also depends on the difference between the hot and cold reservoirs.

PV Diagram

It is the pressure-volume diagram which helps to study and analyze the efficiency of a heat engine. It acts as a visualization tool for the heat engine. As we know that the working substance will be any gas, the PV diagram explains the visuals from the heat engine by considering the ideal gas law. Even though the temperature may vary continuously, the PV diagram helps to explain the three elements of the state of the variables. It also uses the first law of thermodynamics to explain the variations in heat engines.

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If we observe the figure, we can understand that it is the PV diagram of a single cyclic heat engine process. It appeared as a closed-loop. The area inside the loop represents the amount of work we have done in the process and the amount of useful work we obtained. The pressure-volume diagram is beneficial and an advantageous visualization tool to study and analyze the heat engine.

Conclusion

Hence, the heat engine is a system of converting heat energy into mechanical work.  The  efficiency of a heat engine is the ratio of  difference between the hot source and sink to the temperature of the hot source. The efficiency of the heat engine depends on the difference between a hot reservoir and a cold reservoir. We have delivered the formula to find out the efficiency of a heat engine. Also, we can’t get 100% efficiency for any heat engine.

The history of transport is said to largely be one of technological innovation. The advances in technology have allowed people to travel farther distances and explore more territory. Along with that, people can expand their influence over larger and larger areas as well. 

Even in ancient times, there were new tools such as foot coverings, skis and snowshoes that lengthened the distances that could be travelled from one place to another. Here, we are going to discover some more information about transportation. 

Innovation generally continues as transport researchers are working to find different and some new ways to reduce costs and increase transport efficiency.

Evolution of Transportation

                                                            

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The history of transportation generally begins from the human era and continues to change over a period of time. The first means of transportation was the foot of human beings. People used to walk very large distances to reach places earlier. The first improvement that was made to this kind of transportation was adapting to different surfaces as well. For example, we can say that the people who are living in areas with snow and ice, wore spike-like attachments which were there so that they didn’t slip on the ground.

There are people who knew that the logs and the trees float on water and so they dug out the portion that is in the middle of logs to form a kind of seating. This helped people a lot and allowed for water bodies to be used as a means of transport.

It was around 3500 BC that the first vehicle wheels were used. As a means of transporting the loads which were too small, the wheels were attached to carts and chariots. From here people usually went on to tame animals like horses and all as a means of transportation. The animals which are domesticated were used as means of transporting people and small goods.

International trade was the driving motivator behind advancements in global transportation in the Pre Modern world. Then there was a single global world of the economy with a worldwide division of labour and multilateral trade from 1500 onward. The transportation and the sale of textile, silver and gold and spices, slaves and luxury goods throughout Afro-Eurasia and later the New World saw an evolution in overland and sea trade routes.

Introduction of Transport

The history of transportation has taken a very drastic change with the introduction of wheels. This is because of the discovery of the axel and the wheel in other smaller devices like wheelbarrows that came into use. The existing means of transportation were continuously improved thereafter. For example, we can say that the use of iron horseshoes became a common practice. The clubbing of different modes of transportation was then a possibility if we look at it keenly. For example, horse-drawn vehicles as cars or carriages.

From here we see the progress which is related to transportation that started gaining large momentum. The submarines came into existence around 1620 and in the 1660s mode of properly functioning public transportation were available. The carriages and the steamboats, along with the cycles and even hot air balloons became functioning vehicles that were used on a large scale.

The vehicle that was the first gas engine was made by Jean Lenoir in the year 1862 and after this in the year 1867 that is the first motorcycle was invented. Finally, in the year 1903, the Wright brothers designed the first manned aeroplane with an engine. In 1926, there was the first liquid rocket propellant launched successfully! Other vehicles like the helicopter, jets and hovercrafts came after this.

Existing means of transport were said to be continuously being improved upon. The steam engines generally lead to the invention of bullet trains as well. The flight that was manned which was created by the Wright brothers led to a Jumbo Jet! From travelling on foot we have come a long way and different means of travelling have led to a vast network in the external world.

History of Transportation In India

The transport in India generally consists of transport by land, and water and air. Public transport is said to be the primary mode of road transport for most Indian citizens, and India’s public transport systems as well are among the most heavily used in the world.

The network of India’s roads is the second-largest and one of the busiest ones in the world. The transporting passengers were 8.225 billion and over 980 million tonnes of cargo was transported annually as of 2015. Indian aviation is broadly divided into military and civil aviation which is the fastest-growing market aviation in the world as per IATA data and Bangalore with a 65% national share is the largest aviation manufacturing hub of India. 

History of transportation has undergone drastic changes when humans invented the wheels. This was only because of the discovery of the wheel and axle in the smaller devices like the wheelbarrow which were in use. The transportation that was already present was vigorously improved overtime. We can consider the example of the iron horse-shoes which came into practice. Clubbing of transportation modes was a possibility where humans looked keenly. For example, the horse carts and carriages that were in use.  Eventually, the transportation area started gaining momentum largely. The submarines were invented and came into use around the year of 1620 and in the 1660s, the public transportation means were available. The carriages and steamboats were already present and thus came the cycles and even hot air balloons. All of these came in function and were used on a large scale.

Jean Lenoir in 1862 contributed to the invention of the first gas engine in a vehicle. Later, in the year 1867, the first motorcycle was also invented. We all must have heard about the Wright brothers. They made the airplane in 1903 and it was one of the greatest human inventions. Then in 1926, the first liquid rocket propellant was also launched successfully. And gradually, the jets, helicopter and hovercrafts also came into use.  This led to many improvements of all the existing transportation. The steam engines that were in use eventually led to the discovery of bullet trains that we see around us. The airplane which was invented by the Wright brothers then led to the invention of the Jumbo jet. This made travelling around the world easier and convenient. In the past, it took months to travel long distances which can now be covered in some hours or days.