本题目来源于试卷: Quantum Mechanics of Atoms，类别为 IB物理学
[问答题]
Explain how a 0.0005-W laser beam, pho6f.qi x8nyk5auok2b s- f g6r0tographed at a distance, can seem much- sb3aed 8c2mi stronger than a 1000-W street 2 c-ib3de8m salamp at the same distance.
参考答案:
The 0.0005 W laser beam’s intensity is nearly constant as it travels away from its source due to it being approximately a plane wave. The street lamp’s intensity, though, drops off as 1/$r^2$ as it travels away from its source due to it being a spherically symmetric wave. So, at a distance, the intensity of the lamp light that is actually reaching the camera is much less than 1000 W. Also, the street lamp’s intensity is spread out over many wavelengths, whereas the laser’s intensity is all at one wavelength, and film can be more sensitive to certain wavelengths.
本题详细解析:
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