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Minor Versionm

by Procheta Mallik


Cut a PET bottle in half and and connect them using a long string. You can use this to communicate over some distance with the thread being the medium for propagation of sound.

    • be careful while handling scissors and paper cutter or any sharp tool

    • Trim off any plastic scrap on the edges of cut parts of the bottle

  1. Cut the plastic bottle and make sure to trim the scrap off the edges of cut parts.
    • Cut the plastic bottle and make sure to trim the scrap off the edges of cut parts.

    • Take the cap out and make hole just large enough to insert the thread through

    • Tie knot 3-4 times on the other side so that the thread does not come out through the hole when in tension.

    • Repeat the above 2 steps with the other end of the string and other cut part of the bottle.

    • Do same as mentioned in the previous step

    • The speaker uses the lower portion of the cut bottle and the listener uses the portion of the bottle with the cap.

    • The string must be kept taut while using the toy.

    • Measure the length of the wire when fully taut.

    • Next, hold the string such that it is slack and try talking through the phones.

    • What difference did you observe? Did sound become softer or louder? If so, why?

    • Then repeat the experiment with strings of different lengths. Try the maximum length possible. Is sound growing louder of fainter?

    • Use some other material instead of thread. Try with rubber pipes as well as plastic pipes with small diameters.

    • From the speaker side use different sources of sound and listen on the other side.

Finish Line

Vishal Bhatt

Member since: 04/26/2017

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