Call4ljw, don't be too arrogant. Not trying to start a flame war
here, but I feel that you delibrately is trying to be confusing
here; in fact, I'm finding your posts to be not making sense.
And indeed, what I have said is true. And get this: I have never
officially studied physics as a subject in school, having only read
up about it here and there. The concepts I explained should be
rather easily understandable; if you wish to, just go to someplace
like Answers.com or Wikipedia and do a search about it. It
shouldn't take a physics professor to figure out some of the basic
concepts I have explained.
If you still don't understand, then I suggest you go to an MRT
station and look at the entire trainset entering and leaving the
station yourself. Then, go to somewhere around the part of the
train tracks just before Ang Mo Kio, southbound, and take a good
look at the underside of the trains. Then, go to the walkway over
there that gets very close to the tracks before it snakes down
toward the station, and stand there and listen for yourself where
most of the motor's noise is coming from. As for the tunnel one,
try this: stand in an open space and speak to yourself, listening
carefully for your own echo. Now try doing this in a pedestrain
tunnel somewhere, and compare.
I'm not trying to be arrogant.
I'm just using your tone back at you.
For oahiyeel's comment above, he not only makes sense but it
also answers my question and most importantly, he used simple
english in the form of few sentences only.