The discussion revolves around understanding the amplitude of a wave emitted from a line source at varying distances, specifically comparing the amplitude at distances 'r' and '4r'. The subject area includes wave propagation and the characteristics of cylindrical wavefronts.
The conversation includes various interpretations of how amplitude changes with distance, with some participants suggesting that the amplitude is inversely proportional to distance, while others express confusion about the correct relationship. There is no explicit consensus on the final answer, but several lines of reasoning are being explored.
Participants are navigating assumptions about the nature of wavefronts (cylindrical vs. elliptical) and the implications for amplitude and intensity relationships. There is mention of confusion regarding the definitions of amplitude and intensity in the context of the problem.
altamashghazi said:
…altamashghazi said:
altamashghazi said:
sorry wavefronts will be cylinderical out wards but i couldn't guess the pattern of change in amplitude.tiny-tim said:why??
altamashghazi said:
tiny-tim said:yes!
ok, then how is the surface area of a cylinder related to radius?
, so if you draw the field lines, they'll all be radially outward,tiny-tim said:ok
and the number going through any wavefront will be proportional to r …
so what is the loss in strength?
but its wrong the answer is a/2. therefore i m confused. pls help.tiny-tim said:yup!
thank u very mucchtiny-tim said:oh, I'm sorry, i thought a was the intensity
the intensity (as shown by field lines) is proportional to 1/r,
and the amplitude is proportional to the square-root of the intensity
tiny-tim said:oh, I'm sorry, i thought a was the intensity
the intensity (as shown by field lines) is proportional to 1/r,
and the amplitude is proportional to the square-root of the intensity