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# Daily Archives: December 6, 2011

## Fine Structure Constant

Please tell me what is fine structure constant? (Asked Deepanshu Gabba )

A fundamental and dimensionless physical constant, equal to approximately 1/137, that occurs in expressions describing the fine structure of atomic spectra

In physics, the fine-structure constant (usually denoted α, the Greek letter alpha) is a fundamental physical constant, namely the coupling constant characterizing the strength of the electromagnetic interaction.

## The “Pulling Power” of flame

I would like to ask : does flame has its own pulling power ? e.g. when we blow out a candle , the wick often seems to be goin      with the blow . is it coz of our blow or is it the flame carrying it along with itself ? (Bikramjit Singh asks)

## A Problem based on Friction

an unloaded bus can be stopped by applying brakes on straight road after covering a distance x. Suppose, the passenger add 50% of its weight as the load and the braking force remains uncharged, how far will the bus go after the application of brakes? (velocity of bus in both case is same)

## Problem from Kinematics

Devika posted:

There are two particles A and B moving with same velocity u such that initially there velocity are perpendicular to each other and distance between them is L.the velocity of A is always directed towards B.find the distance between them after a long time.

Ans will be posted soon

## Potential

find the potential at A ….a prson brings a mass of 1 kg from infinity to the pt A .initially the mass was at rest but it moves at a speed of 2 m/sas it reches A .the work done by person on mass is -3 J

Ask Physics has installed the Latex server and now users can type latex code to insert complex equations to their comments or questions.

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$(a+b)^{2}=a^{2}+b^{2}+2ab$

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