1Philip?
The power transferred through any cross section of a string in a standing wave is zero.
True or False
-
UP 0 DOWN 0 1 18
18 Answers
1@ Anirudh : To me it seems as irrelevant as the previous one...
@ xyz : pls can u elaborate...
1so u are not convinced with explanation given by me
i am sure u didnt read coz i gave it
the explanation was given in resnick halliday krane now i am sure u will read [1]
i am telling becuse it very well explains ur second question
1@ utd forever I like your statement "Power cannot be transferred across the nodes of a standing wave since they are fixed"
nice and precise
so what would the answer be for any other cross section ?
what about the antinodes for instance
1@philip
as said by utd4ever
the entire energy is localised in single loop
so power transmitted is 0
u can look at this way also :
the entire loop (between the nodes)
is an isolated system ,the neighbouring particles on either sides of nodes do no work ...hence the energy of isolated system is always constant , so no power is transmitted
but u see in the case of standing wave
the its not an isolated system and the neighbouring particles do do the work making the energy variable of time
interesting thing that happens in travelling wave is that
both P.E and K.E become max at one ponit and become 0 at another point
but u can very well compare the standing wave within a loop to a spring mass system
for mathematical proof , see anirudh's chatbox
1Power cannot be transferred across the nodes of a standing wave since they are fixed and so the energy is localised in a single loop ..
1philip its easy,apply simple logic
in standing wave u see the mechanical energy is not transported
coz its not TRAVELLING ,
since the energy is localised
dE/dt =0 !
1can we we say it like
energy associated with any element is proportional to square of amplitude. in a standing wave different element may have different amplitude which are constant . thus energy associated with different element may be different.
also in travelling wave there is continuous influx of energy which maintains there amplitude. where as in standing wave total energy is constant. if power was being transferred then amplitude of different elements will change .
diff. element have diff. total energies which are const.
i think now it is correct?
1well the amplitude of any element may not change even in a travelling wave.
e.g in a sinusoidal wave y = A sin (wt - kx) the amplitude of each element is A and remains so.
this is a very irrelevant reason.
1amplitude of any part of standing wave do not change over time. this could not have happened if energy was being transferred .
1well you must have had sufficient evidence to say so...
so please provide it.