Recent content by lavster

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    Excel - linest function with blanks help

    Hi, Ive been trying to use the linest function with blanks but I can't get it to work... (specifically =INDEX(LINEST(E6:E16,A6:A16^{1,2,3}),1). Here A6:A16 is a number increasing in increments of 1 between 25 to 35, and E6:E16 is only filled if the corresponding measurment is made. Does anyone...
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    Determine the uncertainties

    Great thanks :) any idea why it is the same as the uncertainty in a single measurement... Just doesn't seem right to me! Xxx
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    Determine the uncertainties

    Homework Statement what is the uncertainty of \frac{a+b}{c+d} if a=b=c=d and σ_a = σ_b =σ_c=_d Homework Equations σ_{a+b}=√(σ_a^2+σ_b^2) σ_{\frac{a}{b}}=√((\frac{σ_a}{a})^2+(\frac{σ_b}{b}^2)) The Attempt at a Solution since a=b=c=d σ_{a+b}=√2 σ_a σ_{\frac{a}{b}}=√2...
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    Statistics: detectibility of two objects, with 95% confidence

    Homework Statement Apologies if this is not meant to go into homework area; this is not a homework or coursework question, but more to convince myself that what I am reading is correct I have attached the diagram I am pondering over... How can I prove that if I want to differentiate...
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    Area under v vs t sinusoidal trace

    if I have a sinusoidal trace on an oscilloscope (v vs t) and I wanted to find the area under the wave form squared graph I could integrate the sqaured waveform with respect to t. but since i don't have the integration facility... is it fair to say that the area under the graph is proprtional...
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    Why does a change in impedance cause reflection?

    why does a change in impedance causes reflection? I know that R=(Z2-Z1)/(Z1+Z2), but what is it that makes the wave be reflected? thanks
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    If i have a=exp x, and i know that my uncertainty in a is 3% ( at all

    so dx = da/a? so the absolute uncertainty in x is equal to the percentage uncetainty in a?
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    If i have a=exp x, and i know that my uncertainty in a is 3% ( at all

    if i have a=exp x, and i know that my uncertainty in a is 3% ( at all points). At a point where a=2, how do we calculate the uncdrtainty in x. is the absolute value = (3% of ln 2)/ln 2, which equals 0.03mm, which equals 1% (if x is 3mm) thanks
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    Trying to calcualte the uncertainty

    Thanks :) is this just differentiation? So delta F(A) = da times dF/da ?
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    Trying to calcualte the uncertainty

    if i have two repeat measuremetns, A and B, is the following correct? I am trying to calcualte the uncertainty... I know there are easier ways to do this but i need to have the uncertainty of the mean in terms of δ(A-B). from pairs of measurements A and B at each setting we have...
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    Percetnage by volume of propanol from original volumes

    if i had 500ml of water and added 250ml of propanol, how would I go about working out its percentage by volume? thanks
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    Calculate P-Value: Compare Method1 vs Method2 Results

    Homework Statement This isn't a homework question but figured this is the best place to ask :) what I have done is measure doses from an x-ray tube at various positions using two different methods, method1 and method2. I would like to say if they are statistically significant or not by using...
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    What affects the speed of sound - does viscosity?

    Ive just noticed all these posts - thank you! (sorry for the delay!)
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    LaTeX Latex - graphs closer together

    ive got to give a hard copy... They have lots of rules incl fig size, margin size, font size etc etc :( thanks ill have a play!
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    LaTeX Latex - graphs closer together

    the graphics size is fine, and the white box is too. i have know idea why this is happening! :(
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