Featured articles Passenger in a moving trainMay 12, 2012A passenger in a moving train tossed a coin which falls behind him .State the type of motion of the train ? Answer: The train is in accelerated motion. Explanation If the train were moving with uniform velocity, the coin would fall back to the passenger's hand (This is due to the inertia of motion of the coin. When it was thrown 'vertically' up, it had the same horizontal velocity as that of the train. Therefore, it will move alongwith the train and fall back to the thrower's hand... Read more Bouncing ball and energy dissipation problemMay 2, 2012Please help me with the question below.. I'm totally confused! A player throws a ball of mass 0.6 kg into the air, to a height of 4.0 m above the ground. The ball then falls to the ground. During the impact, 22% of the ball’s energy is lost. Calculate the height to which the ball rises after the bounce. Your assistance will be appreciated.. Mustafa posted Answer: m= 0.6 kg h = 4.0 m Energy = mgh During impact 22% energy is lost. Therefore, energy remaining = 88% Therefore the en... Read more How does a microwave oven work?April 27, 2012Now, microwave oven is so popular that majority of houses have one. Many use it mainly to reheat food without loss of nutrient. The advantage is that the microwave heats up the food very fast. Some observations made on microwave oven are, It does not heat up the vessels directly It is not able to cook food contained inside metal vessels If the turn table does not work, cooking will not be even. So, it is pertinent to ask how the mechanism of heating in a microwave oven... Read morewhen no light is present so why do we see black colour ?April 25, 2012When no light is present so why do we see black colour ? Praveen Kumar asked Answer: Black is not the color, it just denotes the absence of light. When there is light, an object is seen black when it absorbs all light incident on it. Read more Relative DimensionsMarch 19, 2012Could u pls read my below theory of the universe [Ramkumar posted this] and pls contact me when done with ur real frank comments..... Assumption:Matter is Infinitely divisible... Hypothesis: if so we can infinitely into the micro and levels... Matter can be divided into many levels upon their size Theory: this that only result of 1 level affects the above and below levels... the levels are consistent... i.e the levels are complete in their sense.... this whole theory is ... Read more String TheoryMarch 13, 2012String theory suggests 11 dimensions. If the Big Bang involved a sudden expansion of three of those dimensions into the space we know today, is it possible that the energy for the Big Bang and subsequent expansion was caused by the collapse of one or more of the other 8 dimensions into the tiny form they allegedly inhabit today. The form of the before the Big Bang is unknowable but is this hypothosis possible? Related articles String Theorists Simulate the Big Bang (livescienc... Read moreINTENSIVE VARIABLES AND EXTENSIVE VARIABLESMarch 10, 2012A thermodynamic variable may be intensive or extensive. What are intensive variables? The variables which are independent of size or amount of substance are called intensive variables. Example: Density is an intensive variable. (because it does not depend on the amount of that substance) What are extensive variables? The variables which depend on the size or amount of the substance are called extensive variables. It is additive for independent, noninteracting subsystems Example: Mass and volume are extensive variables. (Because they are directly measuring the amount of substance) Read moreUmbrella Rain and SunMarch 6, 2012Rain is falling vertically.A man running on the road keeps his umbrella tilted but a man standing on the street keeps his umbrella vertical to protect himslf frm the rain...But both of them keep their umbrella vertical to avoid sun-rays... EXPLAIN.....!!!! Read moreHow long does it take for a ball to fall to the bottom of a coneFebruary 28, 2012Definitely not a homework question here, just a game that friends and I try to play to guess how long it takes a ball to fall to the bottom of a cone. I do not have a lot of physics experience, but I was under the impression that if we knew certain constants such as: the diameter and height of the cone, the mass of the ball, the velocity of the ball as it falls into the cone, the angle of the side of the cone, and the usual constants for gravity and friction - that we should be able to know the exact time the ball will fall to the bottom. We should also be able to know the distance the ball travelled going around the cone before hitting the bottom. Sadly, I am not quite able to work out how to guess either the time or distance. Any suggestions? Read more Rate of change of acceleration?February 27, 2012What is the name for rate of change an acceleration? (P. Selvam asked) Answer: The rate of change of acceleration is called Jerk or Jolt Just for info:yank (symbol Y) has been suggested for rate of change of force, tug (symbol T) for rate of change of yank, snatch (symbol S) for rate of change of tug and shake (symbol Sh) for rate of change of snatch. Read more Scientists Agree Again – Light is the Fastest not neutrinoFebruary 26, 2012Year 2012 started with a struggle among the intellectuals and scientists when CERN released the finding that "Neutrinos travel faster than light" But, now the scientists of CERN suspect that it could be an error in measurement of time that caused the faulty calculation. They are blaming the loose connection in Fibre Optic Cables and the GPS signals. A GPS correction applied to the time sensor after triggering the neutrinos could have caused the error in measurement of time. The ex... Read more |
http://scienceblogs.com/startswithabang/
http://www.cosmosmagazine.com/
http://www.guardian.co.uk/science/series/science
http://www.last-word.com/index.php
http://www.nasa.gov/audience/forkids/kidsclub/flash/index.html
https://project-cernland.web.cern.ch/project-CERNland/index.html
http://www.sciencefairstl.org/
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