physics pls help...propagation of sound?

hi. im studying in 9th std. im from india. i have to take physics class about" propagation of sound " tomorrow. i want some simple details about that. (i have to explain that). (which is easy to understand) i want some examples and some question and answers. pls help.. thanks

Update:

how does sound propagate...?

Update 2:

i dont have any books about sound and i searched on wikipedia , its not that much clear.

7 Answers

Relevance
  • 9 years ago
    Favorite Answer

    these are some simple points related to sound

    1.sound is a form of energy

    2.it causes sensation of hearing on reaching the ear

    3.any vibrating body could be a source of sound

    4.sound needs a medium to propagate

    sound cannot travel in vacuum.that is why we cannot hear anything in space as there is no medium

    5.sound can be classified into 3 types based on its frequency

    frequency is the no. of waves that cross a point in 1sec.foe ex:if 200waves cross a point in 1 sec the frequency of the sound is 200Hz [hertz , unit of frequency ]

    6.audible ,sound freq range 20-20,000Hz

    ultrasonic , freq above 20,000Hz

    infrasonic , freq below 20Hz

    • Login to reply the answers
  • Anov
    Lv 6
    9 years ago

    Sound wave is called longitudinal wave because it travels longitudinally in the direction to the propagation of the wave.It is a mechanical wave. To produce sound wave there needs a disturbance.

    Like you see the waves in the river or in the sea which is due to the air flowing at its surface or due to the internal disturbance.So to say, when there is a cause there is an effect. Here Air or internal disturbance is the cause and the effect is the wave.Similarly when you strike, for example, strike a metal pie at its one end and you hear the sound at its other end very easily.The travelling mode of these waves are longitudinal.To make still more, take a piece of wood of which the mid part of it is vertically slit.Pass a long piece of thread through this slit.Hold the one end of the string and the other end also some body to hold it. Now get somebody to hold the slit- wood vertically.The string has to be reasonably taut .Now either of one of who is holding the string can move his hand up & down so that the string(Thread) starts moving up and down.Now you will see the vibration of the string with waves travelling through the slit longitudinally.Similar is the case with sound wave. I think the example makes you clear how does sound wave propagate.Thank You for your question.Note: Sound needs medium to travel.It cannot travel in vacuum.

    Source(s): Do the experiment as mentioned above, or similar experiment. You can study any book relating to Basics of sound at the library.
    • Login to reply the answers
  • Anonymous
    9 years ago

    sound is a form of vibration and any vibration needs a medium thus sound needs a medium called air water etc. to propagate, sound is nothing but a disturbance caused by any source for e.g. when u hit on a table d disturbance caused there is propagated in form of waves in all directions and it can b heard by any person

    see this also

    http://www.youtube.com/watch?v=MFLeGJclQiI

    Youtube thumbnail

    &feature=related

    http://en.wikipedia.org/wiki/Sound

    http://www.youtube.com/watch?v=HVGE854x1yQ

    Youtube thumbnail

    Source(s): you tube, wikipedia,self
    • Login to reply the answers
  • 9 years ago

    You may refer to some books like S. Chand's Lakhmir Singh and Manjeet Kaur, or you may refer to NCERT. You can also search on Wikipedia.

    • Login to reply the answers
  • How do you think about the answers? You can sign in to vote the answer.
  • 9 years ago

    i have a soln 4 u . first of all sound moves by disturbing the air molecules near it speed of it is 330 m/sec

    sped varies with medium sound is faster in water.

    • Login to reply the answers
  • 9 years ago

    say her/him that sound travels through air originates through vibrations and propagate through oscillation of particles just say these words

    • Login to reply the answers
  • 4 years ago

    Note: I don't know how to post the symbols B = 10 dB log ( I2 / I1) 12 = 10 log (ratio of intensities) 12/10 = log (ratio) To get rid of the logs, the equation to the 10th power: 10^(1.2) = ratio Answer: Ratio = 10^1.2 = 15.849

    • Login to reply the answers
Still have questions? Get your answers by asking now.