Physics Demo Number: 179
Approximate
Run Time: 10 min
Transverse Standing Waves in a Rubber Cord fed by a Motor-Driven Rod
Demo Description
A very old motor-driven- rod apparatus has been streamlined (and put on a dedicated cart) for producing transverse waves in a rubber cord.
Scientific Principles
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Standing waves can be realized in a cord fixed at one end and driven by a transverse periodic pulsing mechanism at the other end, if an appropriate tension is maintained in the cord.
Equipment
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A dedicated motor and driven rod apparatus
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A permanently attached rubber cord
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A dedicated cart and permanently attached holding fixtures for the moving parts
Equipment Location
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On a dedicated steel cart at the wall end of aisle between [E] and [F] Columns
Instructions
The first two pictures show the front and back view of the apparatus sitting at the prep room door. The far end of the rubber cord has been tied to a stairway hand grip on the hall side of the lecture room.
The third photo was taken from near the tie off point of the cord.
One can see that the camera has frozen the instantaneous position of the cord.
One also sees the dedicated metal cart containing the entire apparatus in the third photo.
The clean, user friendly setup has been made possible by assistance from the Science Machine Shop .
Actual setup time is now probably less than 2 minutes.
One may vary frequency, for fixed tension, or vary tension for fixed frequency.