Suppose there is a planet, the traffic law there is~(adsbygoogle = window.adsbygoogle || []).push({});

car should stop if the traffic light in infrared region,i.e wavelenght ~10^-5m, otherwise the driver will be fined.

There is a driver claimed that he saw the traffic light still in the X-ray region i.e wavelenght ~10^-10m when passing the traffic light so he hadn't violated the law

If possible, what will be the speed of the car~

However, I found it is impossible for the driver to have this dopper shift, as the speed of the car will be about 600c ~

I did in following step:

by the formula of dopper effect for SR

[(1-v/c)/(1+v/c)]^1/2 = L0/L = 10^-5/10^-10where L is the wavelenght

L0/L = 10^5

the RHS value is so large~

so I expand the LHS as:

(0.5 - 0.5V/c) (0.5+ 0.5v/c) than I get the value as v~600c!!

What's going wrong, can anyone help me!!!!

yukyuk

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# Homework Help: Dopper Effect in Special Relativity

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