Will the train whistle have a higher pitch as the train approaches you or after it has passed by?Why?
923187
Since sound travels faster than the speed of the train,there will be overlapping of sound as it approaches you (i.e Doppler effect) the pitch is high and highest when it crosses you..The closer you are to the track ,more will be the effect.As the train passes away from you the sound dies down in a drawn out fashion.
75606
Since the orifice is in the bottom of the tank and water starts flowing out vertically -downwards-the weight of the railway tank decreases as the water in it decreases. Therefore the pressure exerted by tank on the rail track decreases.The track which was depressed earlier now elevates itself depending upon the reduction of weight.The water tank raises up a little. But the elevation is too small to measure by ordinary methods. Using optical instruments we can measure the elevation. \n On the other hand if the water flows horizontally from the orifice the water will trace a parobolic path.Due to conservation of momentum the tank with all its contents will begin to move in the opposite direction. When more and more water flows out, the tank gains more and more momentum. The speed of the tank increases accordingly. Finally it will move with a constant velocity which it gained lastly when all the water in it is emptied. \n\nIt is worthwhile to study the motion of rockets at the same time.Instead of railtank we have rocket and instead of water  we have gas coming out with treamendous velocity which provides an upthrest to lift it and move it to greater height.
947506
no.\nsound waves travel faster in warm temperatures than in colder ones.\nWhile sound does travel faster in warm air, it doesn't necessarily travel farther. If sound is traveling over a warm area, the temperature normally decreases with increased height, thus the top part of the horizontally traveling sound wave will propagate slower than the lower part. This causes an upward refraction of the sound, bending it away from the ground. However, over a cold area, such as a frozen lake, the upper air may actually be warmer than the lower layer of air. This causes the sound wave to travel faster in the upper region resulting in refraction of the sound towards (along) the ground. And the sound will "travel" farther over the cold surface than over the warm surface.
930735
Is the person next to you moving at the same speed as you?  If so you'll hear him fine.  If he's not moving at all then you'll never hear him, as the sound can't catch up to you.\n\nImagine another scenario to understand what I mean.  You're on an airplane which is stationary (say it's parked at the loading gate) and you're running down the corridor of the plane.  You can reach a maximum speed of 30 km/h.  Now, if the plane is moving at 300 km/h and you're running up the corridor, you're moving effectively at 330 km/h.  It's the same with the sound coming from your mouth.  If you're moving at a speed of X, when the sound comes out of your mouth, it's moving at a speed of X + roughly 350 m/s (the speed of sound).
384414
Get a friend (or just do it yourself) to lead a sing-along on a train, subway car, or bus and see what happens. This is something I've wanted to do for a long time, but never have as I don't want to get beaten up by people who think I'm annoying. Several reasons why this might/might not be worthwile:\n-It definately breaks the social norm. Not many people like to be heard loud and clear when they're using public transportation.\n-Very few people actually will sing in public. Most people will only mutter or completely ignore you when you ask them to sing.\n\nGood luck :)
1032236
I agree with a number of the other posts that you should state the question correctly. One doesn't see thunder, but I'm assuming you are talking about the light from the lightning that created the thunder.......yes?\n\nAnyway, with such an assumption, and based on the numbers in your question, you will see the lightning from the northern-most strike before you see the one from the south.\n\nThe train will have moved roughly 0.475 inches when the lightning flash reaches the observer, and therefore this ligtning flash has this much less to travel before reaching the train.\n\nIf you're actually talking about thunder......or....sound, you'd still hear the nothern-most thunder first.
486575
Provided the bridge is not high enough, the vertical component will not change.\n\nThe tep. will remain constant if the train is in uniform motion.
997346
See this all depends.... if this were in the philosophy section, then it could be debatable.  But alas- it's in the botany section, so yes- it does make a sound.  Friction is created as it falls through the air and hits the ground, and that friction causes soundwaves.  Whether someone is there or not is irrelevant.  Humans can only pick up on a certain range of decibels anyways.  That doesn't mean just because we can't hear it, it doens't make a sound.  It just means that we can't hear it.  People need to get unstuck from themselves and think outside the human box.  "If humans can't.... must not be possible."  Meh.
857683
Ah, the quick little tune with the high whistle.
557017
This is called a myclonic jerk.  Check out http://en.wikipedia.org/wiki/Myclonic_jerk for more information.
730076
Yes it would still make a sound eventhough there is no one there to hear it because sound waves would be generated. I think the philosphical question asks whether it make a NOISE. There is a difference between a sound and a noise. A noise is a sound that is loud and unpleasant. That is a judgement call; therefore, it would necessitate someone there to hear it and make the call.
66296
It was pretty clear from the first answer but it was made a little bit clearer when put to me like this.  Have you heard a train horn coming toward you  then away from you?  The same horn at first sounds higher in frequency as the waves are compressing together in front of the train.  Then as it passes, goes away the same horn sounds lower in frequency because now the waves are stretching out, reaching us at a lower rate per second this is the doppler effect.\n \nDoppler is how the Police catch you speeding!  The early radar units were actually calibrated by the officers in the field using the motion of a common music tuning fork! (The back and forth motion of a certain note represented a certain specific MPH).\n\nDoppler really only refers to the change of frequency reflected from the target. If it is higher, then the target is coming toward the receiving antenna.  If it is lower in frequency, the target is going away from the receiving antenna.  The more the frequency shift, the faster the movement. \n\nConventional radar only shows the return signal, and does not measure its frequency shift from that which was transmitted.\n \nHope this helps you.
274177
The volume change is only a matter of distance from the horn to you.\n\n As a sound emitter approaches you, the frequency change, doppler effect, is caused by the shortening of the wave length as the back end of the wave is "compressed" against the front of the wave . Shortened wave length equates to higher frequency for approaching sounders. \n\nAs an emitter moves away from you, the back end of the wave is stretched out away from the front end of the wave, the wave length increases, and the frequency decreases.
439133
Yes.  If you shorten a string on any stringed instrument to half its length, the pitch goes up exactly one octave.
1118118
On a steam locomotive, the "toot toot" whistle uses steam from the boiler to make the noise.  Each locomotive engineer had his own distinctive style of "toot toot".
506978
If its quiet in the morning time I can hear the bell from the train at Disneyland and the whistle from the paddle wheel boat.
223325
Back the train up, past the fire