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Catalogs Discussion Forums -> Integral Calculus -> integration of squrt(sinx) -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]

Its based on elliptical integration ..something at which I  was good at ..but forgot all of them in dues course of them ......hope experts give u a good answer .

Images Images -> goiit_user_images -> Count how many 007s are there ! The winner will get a prize personally from me ! -> Go to message
This Post 5 points    (Olaaa!! Perrrfect answer.   in 1 votes )   [?]
Count how many 007s are there ! The winner will get a prize personally from me !
Catalogs Discussion Forums -> Physical Chemistry -> THERMOCHEMISTRY -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]

I think  the second one is correct . In an endothermic reaction energy is absorbed with increases the P.E. of the reaction intermediate .So the products cannot be more stable than than the reactants . So of course , reactants of the endothermic reaction are highly energetic than products and that is the reason they react so as to decrease their mutual P.E. and transform into much stable products.

Catalogs Discussion Forums -> General Physics -> if a bird sits on a high voltage cable then its feathers tendes to spreads why ? -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]

so as to create a comparativey high potential difference for the high "voltage" cable so that the current can flow through .Electicution is caused only when you ouch two lines simultaneously.Touching one line will not cause anything.since the bird is sitting on only one line solong as its tail touches the other line nothing will happen

Community shelf Community shelf -> SHORTCUT TECHNIQUES -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
Already knew these before . Anyways , gud work putting it up here .
Catalogs Discussion Forums -> Organic Chemistry -> rates assured -> Go to message
This Post 5 points    (Olaaa!! Perrrfect answer.   in 1 votes )   [?]

ag.udel.edu/anfs/faculty/kung/articles/hay_preservatives.htm


 


www.answers.com/topic/propionic-acid


 


www.snowdriftfarm.com/potassium_sorbate.html


 


these many including the above ones , should be enough !

Catalogs Discussion Forums -> Analytical Geometry -> Two vertices of a triangle are (5, -1) and (-2, 3). If the orthocentre of the triangle is -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]

the  third vertex is



either ( 7/2 , 9/2 ) or ( -1/2 , - 5/2)

Videos Videos -> goiit_user_videos -> barbie girl - aqua -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
barbie girl - aqua
Images Images -> goiit_user_images -> -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
Community shelf Community shelf -> Doppler effect of Sound -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
Just for the record guys , I did not create so much of blank spaces ...its automatically getting created even if I am trying to remove them . Anyways , comments plz ...
Community shelf Community shelf -> Doppler effect of Sound -> Go to message
This Post 77 points    (15 Olaaa!! Perrrfect answer.   in 16 votes )   [?]
The Doppler Effect in Sound Waves






Hii guys , your friend Ken has come up with another article ..but this time its even more interesting .




 




 




The Doppler effect is a phenomenon observed whenever the source of waves is moving with respect to an observer. The Doppler effect can be described as the effect produced by a moving source of waves in which there is an apparent upward shift in frequency for the observer and the source are approaching and an apparent downward shift in frequency when the observer and the source is receding. The Doppler effect can be observed to occur with all types of waves - most notably water waves, sound waves, and light waves.Well guys , here I am keeping the topic to be for sound waves .




The Doppler effect is observed because the distance between the source of sound and the observer is changing. If the source and the observer are approaching, then the distance is decreasing and if the source and the observer are receding, then the distance is increasing. The source of sound always emits the same frequency. Therefore, for the same period of time, the same number of waves must fit between the source and the observer. if the distance is large, then the waves can be spread apart; but if the distance is small, the waves must be compressed into the smaller distance. For these reasons, if the source is moving towards the observer, the observer perceives sound waves reaching him or her at a more frequent rate (high pitch). And if the source is moving away from the observer, the observer perceives sound waves reaching him or her at a less frequent rate (low pitch). It is important to note that the effect does not result because of an actual change in the frequency of the source. The source puts out the same frequency; the observer only perceives a different frequency because of the relative motion between them. The Doppler effect is a shift in the apparent or observed frequency and not a shift in the actual frequency at which the source vibrates.

 

 




 

 
















Consider a frame of reference in which the medium of signal propagation is assumed to be at rest, and suppose an emitter and absorber are located on the x axis, with the emitter moving to the left at a speed of ve and the absorber moving to the right, directly away from the emitter, at a speed of va.  Let cs denote the speed at which the signal propagates with respect to the medium.  Then, according to the classical (non-relativistic) treatment, the Doppler frequency shift is




 

 

 

 Check out this interesting videos & java animation here in

http://www.falstad.com/ripple/ex-doppler.html

 

 





( source -> www.grc.nasa.gov  & hyperphysics.phy-astr.gsu.edu  )

 

The Doppler shift of plane light waves in vacuum which arrive with an angle phi with respect to the direction of travel is:




v' = v * (1 - cos(phi) * (v / c)) / (sqrt(1 - (v²/c²))





The difference in the classical and relativistic Doppler effects can be seen in the following graph showing the wavelength shift of green light for velocities ranging from v/c=-1 (recession at the speed of light) to v/c=1 (approach at the speed of light). The Doppler shift predicted by classical physics is shown in red and the correct prediction of special relativity in green.






The overlapping of the two curves in the middle of the graph, where velocities are relatively small compared to the speed of light, demonstrates how relativistic effects have little impact at velocities below a substantial fraction of the speed of light. Note how the interaction of the classical Doppler shift and Lorentz contraction affects the two ends of the graph in different ways. For extreme approach velocities, relativity predicts a blue shift diverging toward infinity while the classical equation only halves the wavelength at rest. For large velocities of recession, both classical and relativistic equations show the wavelength approaching infinitely long values; here the Lorentz contraction reduces the amount of the Doppler shift while leaving intact the trend toward infinite wavelength.







I think its enough for u guys to perfectly have a pictorial idea of doppler  effect .Anyways , enjoy the concept and closing....... with fond affection , your lovely friend Ken ..will be back with another one soon .

Community shelf Community shelf -> Some Shortcuts In Limits -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
Absolutely appreciating . But its better to solve the limits rather than remebering the shortcuts .
Catalogs Discussion Forums -> Electricity -> An ammeter is connected to voltmeter by connecting a -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
edison is perfectly right
Catalogs Discussion Forums -> Electricity -> SOMETHING NEW....... -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]

Hey wait a minute , what do u mean by  E ?

Catalogs Discussion Forums -> Inorganic Chemistry -> plzz ans this ques... -> Go to message
This Post 10 points    (Olaaa!! Perrrfect answer.   in 2 votes )   [?]

the acceleration of the centre of mass of the system is given by


 


a =( mB-ma / ma + mb )g


 


Since both the blocks A and B don't move , so a =0


 


 Now solve the equality  mb=ma to get ur answer as 0.4kg .

Catalogs Discussion Forums -> Electricity -> how to perform star delta conversion in a circuit of capacitors -> Go to message
This Post 2 points    (Olaaa!! Perrrfect answer.   in 1 votes )   [?]

Brilliant dude ..I was waiting for such a question . Nobody here knows abt star delta confirmation of capacitors.


Anyways ,It's a factor of 3.



The easiest way to confirm is by checking the power.



Let Vline-line = 1 Volts.



(This means Vline-neutral = 1/sqrt(3) V)



Let Zcap,wye = 1 ohm



Choose freq = 1/(2pi) Hz, so w = 1 radian/second



C,wye = 1/(w*Zcap,wye) = 1 F



Total Power = (Vline-line)^2/Zcap,wye = 1 VAR







Let's guess that impedance in delta is 3x impedance in wye.



Zcap,delta = 3 ohm



C,delta = 1/(w*Zcap,delta) = 1/3 F



Check Power:



Power in each line-line branch = (Vline-line)^2/ Zcap,delta = 1/3 VAR



Total Power = 3 * 1/3 VAR = 1 VAR







So, to convert from wye to delta, multiply impedance by 3.



But, in a capacitor, impedance is inversely proportional to capacitance, so be sure to invert the 3 .

Catalogs Discussion Forums -> Differential Calculus -> monotonicity -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]

there are various ways (graphical , logical ,algebraic , using bounded sum concept etc) . U need to give one or more examples if u want exact understanding !

Catalogs Discussion Forums -> Thermal Physics -> how we can use wien displacement law -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
lamba (max) = b / T , where b = Wein's constant
Catalogs Discussion Forums -> Algebra -> how to find the sums like 1\1.2 + 3\2.3 +5\3.4 - - - - -- to n terms and infinity -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]

"sairaguram" ..yeah ..these type of sums are pretty confusing .Actually these are calculated by using exponential and logarithmic series ...through various manipulations ( like breaking the terms , multiplying each terms with something ...and then deviding and many more ) in the begining steps .Thats why I hate such series ..lol . Anyways , I am trying .I think I have seen this question in particular at many situations of my study times .

Catalogs Discussion Forums -> Magnetism -> transformer -> Go to message
This Post 15 points    (Olaaa!! Perrrfect answer.   in 3 votes )   [?]

We know that efficiency = power output / power inout  = Vs Is / Vp Ip


 Now u have Vs = 12 V and Ps = 36 W


Use the formula P = V2 / R to get the value of R as 4 ohms and then use V=I R to get the value of Is as 3 A


Now 75 / 100 = 3 x 12  /  Ip x 220


 solve to get Ip as 0.21 A

 
 
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