Help with physics Hubbles constant PLEASE.

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MrToodles4
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#1
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#1
Im not too sure with how to go about this question: 1b;

http://pmt.physicsandmathstutor.com/...y%204%20QP.pdf

I know it says the galaxy is red shifted by 15% of their normal wavelengths - but what does it actually mean by this? I don't understand.

Many thanks

MS: http://pmt.physicsandmathstutor.com/...y%204%20MS.pdf
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Joinedup
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#2
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#2
red shifted means longer wavelength - a line in the middle of the visible spectrum is shifted towards red end of the spectrum

e.g. a source emitting 550nm (yellow/green) would be shifted to (1.15 x 550) = 632.5nm (orange)

you want to feed it into the Doppler equation

z=Δf/f0=-Δλ/λ0=v/c

(don't think you do much with z at A level but you'll see it quite often in the literature where it's used as a shorthand... high z galaxy means high red shift galaxy example)
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