Home » 2011 » December » 06

# 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

## Now users at Ask Physics can add equations to their comments and questions.

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

If you are not familiar with latex code, use the following site to generate the code for the equation that you need.

http://www.codecogs.com/latex/eqneditor.php

When you visit the above site you can edit and view the result of the code generate. You have the option to copy the image of the equation or to copy the code itself (what you typed for getting the image equation; not the html code supplied) and paste the code in your comment.

Go, Try it Now!
$(a+b)^{2}=a^{2}+b^{2}+2ab$

### Hits so far @ AskPhysics

• 2,230,157 hits