Experience Weightlessness

Introduction to experiencing weightlessness

As we know that the earth attracts every another body towards its centre. The force with which the earth attracts another bodies is called the weight. The weight of the body on the earth is equal to the product of the mass of the body and the acceleration due to gravity of earth. Here we can say that the weight = mass × acceleration due to gravity = mg. The value of acceleration due to gravity (g) is not constant throughout the earth. The weight of the body changes as the value of the acceleration due to gravity changes. Here we discuss in which situation the weight of the body becomes zero that means the condition of the body is weightlessness.I like to share this Units for Acceleration with you all through my article.


Experiencing weightlessness and conditions related to it


The weight mg of the body is also known as the true weight or the static weight of the body. We become conscious for our weight, only when weight is opposed by some other object. Actually, the secret of measuring the weight of the body with the weighing machine lies in fact that as we place the body on the weighing machine, the weighing machine opposes the weight of the body. The reaction of the weighing machine gives the weight of the body. There are four main conditions in which the body becomes weightlessness. The four conditions are as follow:

(i) When the body falling freely under the gravity the weight of the body is zero. For example, a lift is falling freely; any ball falling from the tower etc. experiences the weightlessness.

(ii) When the satellite revolves in the orbit around the earth experiences weightlessness. The gravitational force acting towards the centre of the earth balances by the centripetal force acting on the body so that the weight is zero.

(iii) When the bodies are at null point in the outer space. After the certain height, the gravitational pull of the earth becomes less and it is more for moon so that the body will feel the attraction force towards the moon. At that particular height where the gravity of the earth balances by the gravity of moon, the body experiences weightlessness.

(iv) When we reach at the center of the earth, we feel weightlessness. As the value of the acceleration due to gravity at the centre of the earth is zero and so, the weight of the body at the centre of the earth is also zero.


Conclusion of experiencing weightlessness


Weightlessness causes very serious problems to the astronauts. It becomes quite difficult for them to control their movements. Everything in the artificial satellite has to be kept tied down. To overcome this problem we create the artificial gravity so that they do not feel the weightlessness.

What Is Synchronous Motor

Introduction to what is synchronous motor

A synchronous motor (electric) is the another name of alternating current motor which converts the electrical energy into some mechanical energy. In the working of the  synchronous motor the rotor is spinning with the coils and then develops the magnetic field which is used to rotates the motor. Synchronous motor’s speed is determined by  pair numbers of the magnetic poles and the number of oscillations of the electric current (a.c) which is the alternating source of electricity.


Description of Synchronous Motor


The availability of the synchronous motors are in the sub fractional and self excited sizes to very high power and operating on the direct current also. The two types of the synchronous motors, which are used generally: one is non excited synchronous motor and the other is direct current excited synchronous motor. The non excited synchronous motors are constructed on the basis of the idea of reluctance and hysteresis designs, and they starts by the are self circuits and they do not require no any excitation supply of the energy. The reluctance design motors have 30 horse power efficiency. In the synchoronous motors there is a need of low torque and we can use these in the instrumentation applications. Synchronous motors are having the toothed rotors in some designs. The main parts of the synchronous motor are:

(i) the startor is the outer part as a shell of the motor which carries the armature windings, this winding is distributed for poly phase alternating current. The armature creates the rotating magnetic field.

(ii) the rotor is the moving part of the synchronous motor. The permanent magnet is produced by the field due to the windings.

(iii) the function of the slip rings in rotor is to supply the direct current to the windings of the wires in the direct current excited type synchronous motors.


Uses of synchronous Motor


Almost the synchronous motors of low horse power are used to provide the constant speed. The synchronous motors of high horse power are used for converting the energy  alternating current in the work which is useful for the different purposes in the heavy industries and the important use is that it work on power factor having value unity, that means the power loss is negligible.

Energy From The Sun Is Called

Introduction on energy from the sun is called:

The energy from sun is called Solar Energy. In fact, the best form of energy available to us is “SOLAR ENERGY”. The sun is the source of all energy. The sun provides us heat and light energy free of cost. The energy obtained from the sun is called solar energy. The nuclear fusion reactions taking place inside the sun keep on liberating enormous amounts of heat and light energy. This heat and light energy is radiated by the sun in all directions in the form of solar energy. The sun has been radiating an enormous amount of energy at the present rate for nearly 5 billions years and will continue radiating energy at that rate for nearly 5 billion years more. Since, the sin is very far away only a small fraction of the solar energy radiated by the sun reaches the outer layer of the earth’s atmosphere. A little less than half of the atmosphere actually reaches the surface of earth. The rest of solar energy is reflected back into space by the atmosphere and also absorbed by the atmosphere as it comes down through it towards the surface of the earth.


Advantages of solar energy


The best form of energy,solar energy which reaches the earth is absorbed by land and water-bodies as well as by plants. The solar energy trapped by land and water-bodies causes many phenomena in nature like winds, storms, rain, snowfall and sea-waves. The plants utilize solar energy to prepare food by the process of photosynthesis. The various sources of energy derive their energy from the sun, the best source of energy.

1. Non-renewable sources of energy, fossil fuels also derive their energy from sun. It is solar energy, which is converted into petroleum and oil.

2. Solar energy does not cause any pollution as compared to non-renewable sources of energy.

3. The solar energy is best form of energy because it is available in a diffused form so it is available to almost everyone on the earth.


Conclusion to solar energy


Finally ,the best source of energy, that is , solar energy is clean. It is a clean alternative to fossil fuels and nuclear power and it will never run out. It’s silent. Solar power can be captured anywhere without creating noise pollution that might otherwise up set neighbours and wildlife. It works wherever the sun shines. It doesn’t matter how remote, solar can generate energy where no other form of power can be obtained. Thus, no danger of damaging our already damaged environment further and you can be part of the Green initiative, lower your carbon footprint, and save our planet from harmful greenhouse gases.

Regular and Diffuse Reflection

Introduction to Regular and Diffused Reflection

When light traveling in one medium strikes a boundary leading to another medium, a part of incident light is through back into the original medium one. This phenomenon is called reflection of light.

Reflection is of two types:

Regular reflection
Irregular reflection or diffuse reflection


Description to regular and diffuse reflection


1.    Regular reflection: When the reflection surface is smooth and well polished, the parallel rays falling on it are reflected parallel to another one, the reflected light goes in one particular direction. This is regular reflection. The smooth and well polished surface is called mirror. Silver metal is one of the best reflectors of light. So, ordinary mirrors are made by depositing a thin layer of silver metal on one side of a plane glass sheet. The silver layer is protected by a coat of red paint. The reflection of light in a mirror takes place at the silver surface. A plane mirror is represented by a straight line, with a number of short, oblique lines showing back of the mirror.

2.    Diffuse reflection: When the reflecting surface is rough, the parallel rays falling on it are reflected in different direction. Such a reflection is known as diffuse reflection or irregular reflection or even scattering of light. In this, a surface will behave as a smooth surface as long as the surfaces variations are small as compared to the wavelength of incident light. As wavelength of visible light is very small therefore, every surface acts as a rough surface and scattering of light or irregular reflection is more common. For example, any object in a room can be seen from all the parts of the room. This is because surface of the object is rough and it scatters or reflects light in all directions.



Regular and Diffused Reflection : Summary


Reflection of light is the phenomenon of bouncing back of light in the same medium on striking the surface of any object.

Different Ways to Conserve Energy

Introduction to different ways of conserving energy:

When energy is saved, the demand for fossil fuels as oil, coal and natural gas is reduced. Less use of fossil fuels means less pollution, lower emissions of carbon dioxide and less global warming.Below is a house that uses various renewable energy and acts as an example for various ways to conserve energy.


Ways of conserving energy


Plant large, shady trees and paint a dark color to a house in a cold climate or a light color to a house in a warm climate. Trees absorb carbon dioxide from the air and give out oxygen.

Do not leave house hold appliances like Air Conditioner, computer, television, radio etc. on while you are out or when not needed.

Do not cool or warm areas that people are not in and close doors and windows in unused rooms.

Replace light bulbs with energy saving fluorescent bulbs.

Air dishes and clothes whenever possible.

Set lower temperature for the thermostat in the water heater, refrigerator and other heating or cooling devices to reduce electricity consumption. This cuts off the current supply sooner than; this is more efficient than using very hot water and then mixing it with cold water before for use.


Use solar water heaters.

Clean air filters regularly in the air conditioners. Free passage of air doesn't stress the device and thus reduce current.

Insulate doors, roofs and windows to reduce leakage of hot or cool air.

Use dishwasher and clothes washer at full capacity to as multiple usage increases electricity consumption.

Whenever possible get a walk, use mass transit or car pool than using your car daily. This reduces fuel consumption.

Use energy efficient appliances- with energy star label; though expensive, they use less current and reduce pollution and over a period of time save money.

Recycle and reuse whenever possible. Avoid packaged products and go for recyclable ones as they reduce pollution.

ways of conserving energy


Conclusion to different ways to conserve energy


From the discussion on conserving energy, we conclude that besides conserving energy, think of ways to use alternative sources of energy like, solar power, wind power, human powered mechanical energy etc.

Diffuse Reflection

Introduction to diffuse reflection:

The light rays travels in the straight line. The ray of light travels with the velocity of 3 × 108 metre per second. If the ray of light travels from one medium to another medium it suffers refraction due to the change in the velocity of light in different mediums. If the ray of light falls on the smooth and polished surface it suffers reflection. Here we discuss about reflection.I like to share this Fundamentals of Fluid Mechanics with you all through my article.


Diffused reflection:


The bouncing back of the light rays after striking from the highly polished and the smooth surfaces is called reflection. The image formed on retina so the we can see the objects is the very important example of reflection. As the rays of light falls on any object, the rays are reflected from the object and then enter in our eye. Now from the refraction of the eye lens the image of the object is formed on the retina. After that, the optical nerves carry the optical signals to the mind as the mind gives the permission to see the object we can see the image of the object very clearly. The reflection are of two types: one is called the specular or regular reflection and the other is diffused or irregular reflection. In the case of regular reflection, it obeys the laws of reflection completely but in case of the diffused reflection, it does not obey the laws of reflection completely. The diffused reflections are done by the non-polished or the slightly polished and non smooth or rough surfaces. As the rays of light falls on a rough and non-polished surface at any angle of incidence then the angle of reflection is not equal to the angle of incidence. Here the rays of light do not follow the first law of reflection. Similarly, the normal to the reflecting surface, incident ray and the reflected ray are not lie in the same plane, so the rays of light do not follow the second law of reflection.


Examples of the diffused reflection measurement:


The examples of the diffused reflection are the reading of newspaper or reading of a notebook. As we read the newspaper the images of the letters can be produce on the retina. Similarly, the ray of light from our body is reflected but the reflection is diffused so that we cannot see our image on the newspaper.

Rotating Magnetic Field

Introduction to Rotating Magnetic Field:

A rotating magnetic field is a kind of magnetic field which ideally changes its direction at an angular rate which is constant. In the working of a motor that works on alternating current, the rotating magnetic field plays a key role as it is associated with its principle of operation. The concept of rotating magnetic field was introduced by Nikola Tesla in 1882. Galileo Ferrari's has done his research independently to introduce some more features of this concept in 1885.



Production of Rotating Magnetic Field


A rotating magnetic field which is symmetric can be produced using as few as three coils. To produce a rotating magnetic field, three coils should be driven by a symmetric three phase a.c. current and one of the phases is shifted to 120 degrees as compared to the other phase. In this case the magnetic filed should be taken as the linear function of the current which is flowing in the coil. The three phases which are 120 degrees out of phase compare to each other when applied to the axis of the alternating current motor then it produces a single rotating vector. This rotating vector follows the magnetic field in the coil and hence produces a rotating magnetic field .



Application of Rotating Magnetic Field


Rotating magnetic fields can also be used in the induction motors because the magnets, which are used, degrades with time and the induction motor use the short circuited rotor instead of a magnet, which is easily follow the rotating magnetic field produced by a stator, which is multi coiled. In the case of the induction motor, the turns of the rotor which is short circuited, develops the eddy current in the rotating magnetic field of the stator which is used to move the rotor by the developed Lorentz force. Such motors are generally not synchronous but they have involved a necessary degree of the slip by which the current will be produced due to the relative motion of the field and the rotor.