(adsbygoogle = window.adsbygoogle || []).push({}); A stationary light source S wit ha natural frequency Fo is viewed in a mirror M by a stationary observer O. The mirror moves away from the observer wit ha velocty of Vrel << c

a) what frequency of light is recorded by a detector attached to the moving mirror

because Vrel << c classical may be used

let F1 be this observed frequency observed

then [tex] f_{1} = f_{0} (1 - \frac{v_{rel}}{c}) [/tex]

is this correct??

b) what frequency in terms of fo will the stationary observer measure for the light reflected off the mirror?

the mirror will now emit the f1 from above wouldn't it ??

sine this mirror is moving away wouldnt the doppler shift be [tex] f_{2} = f_{1} \frac{c}{c+v_{rel}} [/tex]

which would be [tex] f_{2} = f_{0} (1 - \frac{v_{rel}}{c}) \frac{c}{c+v_{rel}} = f_{0} \frac{c-v}{c+v} [/tex]

but i got the second part wrong! Whats wrong with it??

Also when asked for the lowest average speed of atom at some temperature T given some molar mass M

which formula should be used??

is it [tex] v_{rms} = \sqrt{\frac{3RT}{M}} [/tex] or [tex]v_{avg} = \sqrt{\frac{8RT}{\pi M}} [/tex]

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# Homework Help: Doppler effect

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