kids sometimes play w/ a homemade "telephone" by attaching a string to the bottoms of two paper cups. When the

Question

kids sometimes play w/ a homemade "telephone" by attaching a string to the bottoms of two paper cups. When the string is stretched and a child speaks into one of hte cups, the sound can be heard at the other cup. explain how is the sound wave traveling from one cup to the other cup.

Answer 1

Sound is nothing but vibration of certain frequency and it transmits through a medium. In this case sound travels through the strings.

Answer 2

I was glad to know it would work with paper cups. When I was a continually sick child of 5 - 6 years old reading a children's encyclopaedia in bed in the early 1940s (the basis for my entire life and career, as it turned out), the advice there was to "First ask a Butcher for two pig bladders and wash them caerefully with disinfectant" ! Those cleaned bladders were then to be stretched over a framework, or over the end of a large can (with its bottom removed) with the bladder itself stretched taughtly over one end.

In any case, whether it's along a taut string or taut thin wire (as recommended by the pigs' bladder enthusiast), the sound waves hitting the cups (or pig's bladder) can be transformed into waves that travel along the connection, thereby in effect transmitting the vibrations from one end to the other. At the other end, sound emerges again from the finally vibrating surface(s). (The cups and/or bladders act like rudimentary microphone and speaker diaphragms.)

The encyclopaedia article claimed that with pigs' bladders and really taut wire, the sound could transmit between adjacent houses. There was an accompanying photograph of two kids hanging out of their windows talking to one another.

Live long and prosper.

Answer 3

through vibration from the cup to the string. But you have to pull the string straight or stretch it a little bit to vibrate. if you try it with the loose string it will not work.

Answer 4

i didn't even know those thngs actually worked


here is my theory on it:
when the noise goes into the sending cup, the noise is amplified and reverberated throught the cup and the same noise vibrations are sent through the string and when the hit the receiving cup it becomes amplified again into the original noise but due to the inevitable energy loss it becomes muffled

Answer 5

Must be through the vibration of the string, because if you do that without a string you can't hear each other