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Topic: frequency question
Replies: 1   Last Post: Feb 2, 2005 6:59 AM

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 sean Posts: 6 Registered: 12/13/04
frequency question
Posted: Feb 2, 2005 5:09 AM

I would like to get some feedback on a couple
of maths problems I have been discussing with
others recently where we cant agree on the
results.
Problem A) There are two trains of waves travelling
in the same direction towards an observor who is at
point x. Wavelength A is longer than wavelength B
and thus has a higher frequency observed at x
provided the two are travelling at the same speed.
My question to anyone on this newsgroup is if
the speed of wavelength B (the shorter wavelength)
were reduced relative to the speed of wavelength
A would it be possible to arrive at a situation
where the observed frequency of the two at x
would appear to be the same?
That is: would it be possible to reduce the speed
of the shorter wavelength by a certain amount so as
to make its observed frequency appear to be equivelent
to the observed frequency of the longer wavelength?

Problem B)
In this formula below...
I(t) = Imax * ( fR((t-tmax)/s(1+z)) + b ).
where s is known to be 1.1 and z is known to be 0.1
the result of s(1+z) part of the formula is 1.1
and indeed as the formula above is a fitting formula
a full calculation using known t tmax and I etc also
gives s =1.1

However for a second example where z=0 ,s is unknown
and t, tmax and I are unknown is it possible to
calculate s at all from just the above information
only and if so would the result be s=1.21?