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  Question Bank – Work, Energy, and Power 1. Very Short Answer Questions (1 Mark) Define work. Answer : Work is said to be done when a force is applied to an object, and the object displaces in the direction of the applied force. What is the SI unit of work? Answer : Joule (J). State the condition for work to be zero.

The Special Theory Of Relativity: An attempt to explain E=MC 2 -H.S.Varun “Put your hand on a hot stove for one minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute. That’s relativity. “ Albert Einstein. INTRODUCTION : Einstein’s theory of relativity has caught the imagination of the average man more than any other physics theory in history. Yet the theory of relativity unlike many other results of physics is not easily understood by the average man. We can understand the relativity theory fully only by the means of mathematical formulas which make it up. I am here trying to explain the relativity without a lot of mathematics. Without mathematics, we can only state some of its basic ideas and quote, but not prove, some of its conclusions. I have tried my level best to make this article error free and any mistake from my side is regretted. This article is just a basic attempt to explain Einstein’s Relativity in simple la...

String theory is a in particle physics which attempts to reconcile quantum mechanics and general relativity. String theory posits that the electrons and quarks within an atom are not 0-dimensional objects, but rather 1-dimensional oscillating lines ("strings"), possessing only the dimension of length, but not height or width. The theory poses that these strings can vibrate, thus giving the observed particles their flavor , charge , mass and spin . The earliest string model, the bosonic string , incorporated only bosons , although this view evolved to the superstring theory , which posits that a connection (a "supersymmetry") exists between bosons and fermions , two fundamentally different types of particles. String theories also require the existence of several extra, unobservable, dimensions to the universe, in addition to the usual three spatial dimensions (height, width, and length) and the fourth dimension of time. M theory , for example, requires that ...

The Big Bang theory is a cosmological theory of the early development of our universe. Discoveries in astronomy and physics have shown beyond a reasonable doubt that our universe did in fact have a beginning. Prior to that moment there was nothing; during and after that moment there was something: our universe. The big bang theory is an effort to explain what happened during and after that moment. The Big Bang theory states that the universe emerged from a state of extremely high temperature and density in an explosive expansion that occurred around 13.3 to 13.9 billion years ago.

The Amazing Big Bang Theory We all are familiar of the term the universe and the Milky Way galaxy but there was a time billions of years ago when none of these existed. We can’t even imagine it right? Well this is true and our universe, the galaxies all began with a bang, a big bang. Scientists believe that the universe began with a bang about 15 millions of years ago. At the very beginning, the universe was just a minute hot ball, many times smaller than an atom. Inside this ball was everything to needed to make the universe. In the 1930s an American astronomer Edwin P Hubble discovered that light from all distant galaxies is coming from a receding source. This is the only possible explanation of the light spectrum is shifted towards the red end. The real fact is due to Doppler's effect .in 1948 George Gamow a Russian-born-American physicist in a theory concerned with the origin of the light elements, interpreted the Doppler effect as demonstrating the that the ...