KNOW PHYSICS

Force is the most common term in the classical physics or classical mechanics. The type of force that only occurs when the two surfaces are in physical contact is called as a contact force . One of the example of contact force is friction. Friction is considered as an electromagnetic force. This is confusing for most of the people to imagine friction as an electromagnetic force, but it is. There are charged particles on both the surfaces. When there is a motion the forces that are exert by the charged particle on each other opposes the relative motion of both the bodies. This force is called as frictional force. One of the main characteristics of frictional force is that it opposes the relative motion between 2 bodies. For an example -    Let A and B be the 2 bodies that are in contact and have relative motion. Suppose A is moving more faster than B. So in this case where the friction will act on both the bodies? Be clear that friction wants to oppose relative motion

Light in Seventeenth century In seventeenth century, there were very less facilities for experiments. But the nature was nature, as it is now. Many major behaviors of light was known at that time- Light cast shadows . Which shows that light travels in straight line. Light is reflected from smooth surfaces. The rules of reflection are- (i) The incident ray, the reflected ray and the normal are in the same plane (ii) The angle of incidence is equal to the angle of reflection. When light is travelling from one medium to another medium, it bends unless it falls on the second medium normally. The rules of this phenomenon, called refraction , are: (i) The incident ray, the refracted ray and the normal are in the same plane  Light comes in different colours such as red, yellow, green, blue, violet, etc. All the scientist were trying to understand that why light shows these characteristic behaviors of straight line motion, reflection, refraction, colours, etc Newton's corpuscle theory

The man who invented the 20th century is none other than Nikola Tesla. He is serbian-american inventor, electrical engineer, mechanical engineer and a futurist. Best known for Alternating current(AC) and electrical supply system. Nikola tesla  Born - 10 July, 1856. Died -  7 January, 1943 (83 years). Beginning with a quote of Nikola Tesla- " The scientists of today think deeply instead of clearly. One must be sane to think clearly, but one can think deeply and be quite insane. " Eidetic Memory  Tesla read many works. He can memorize complete books. He supposedly possessed a photographic memory. He was a polyglot, speaking eight languages: Serbo-Croatian, Czech, English, French, German, Hungarian, Italian, and Latin. Tesla related in his autobiography that he experienced detailed moments of inspiration. He often see blinding flashes of light before his eyes, also accompanied by visions. Many times the visions were related to the word or the idea that he was currently wor

MAGNETIC FIELD Today we are going to talk about magnetic fields .   (Suggest more topics in the comment section) The fundamental problem electrodynamics hopes to solve is this(figure): We have some electric charges, q1,q2,q3,...........(call them source charges); what force do they exert on another charge, Q (call it test charge)? The position of the source charges are given (as functions of time); the trajectory of the test particle is to be calculated. Source charge and test charge According to the principle of superposition , it is sufficient to find the force of a single source  charge- the total is then the vector sum of all the individual forces. In the simplest case, electrostatics, the source charge is at rest(though the test charge need not be). We will consider the forces between charges in motion. To give you some sense of what is in store, imagine that I set up the following demonstration:  Two wires hang from the ceiling, a few centimetres apart; when I turn on a current,

Let us first understand what gravity is. Gavity also known as gravitation, is a phenomenon (not a force) of attraction of all the things that have mass-energy like planets, galaxies and light towards one another. What happens: when an object is freely Falling? Don't get confuse between gravity and Gravitational Force. They are separate terms. Gravity is a natural phenomenon. Whereas, Gravitational force is a force that is a measure of attraction. Gravity is the phenomena or cause of, why we are able to stand. Whereas gravitational force is responsible for our weight. If you go to moon then your weight becomes 1/6th of  the weight on earth. Gravity is the reason, why planets revolve around sun., and moons revolve around planets. It is the phenomena, which plays an important role in galaxy formation. Most of the galaxies have a black hole as their centre. Black hole have very large gravitational effect. Now from Newton's laws of motion , we know that ac

Many of you have an image of Sir Isaac Newton. You probably think Issac Newton as a person who contributed immensely in Physics through his laws of motion, gravitation which were the foundation of classical mechanics which we study today. Was Isaac Newton an alchemist? Or many of you think Isaac Newton as a mathematician who invented calculus(debatable). Or the person who proved the society wrong by proving that the light is made up of different colours, with his research on optics. But there is also an other side of his personality. He was heavily interested in alchemy and other occult practices. The world came to know this side of him by the unpublished papers written by him on these topics. Sir Isaac Newton was heavily involved in Alchemy . It is considered as an occult science. Alchemy is the medieval forerunner of chemistry, concerned with the transmutation of matter, in particular with attempts to convert base metals into gold or find a universal elixir. S