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How Do Police Radars Really Work?Problem:
Solution:
Since the photon energy, E, is equal to hn, where h = Planck's constant = 6.63 X 10-34 j sec, then Also,
since photon momentum equals h where
the first term on the RHS represents Dividing
eq. 1 by eq. 2,
and substituting for
This equation may be simplified to read
where
the final step results from V << c. Now, let V = 60 mph = 27 m/sec,
and let
The police radar detector easily detects this frequency shift. |
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