**TAP 324- 9: Stationary waves in a string**
This is a question about stationary wave patterns set up in a vibrating string.
**A vibrating string**
An elastic string is clamped at both ends. Near one end a vibration generator is loosely attached. The vibrator oscillates with fixed amplitude but with variable frequency. A graph of maximum amplitude along the string against frequency of vibration is shown.
Sketch the instantaneous appearance of the string at:
1. 15Hz.
2. 30Hz.
3. 45Hz.
4. What is the wavelength of the waves on the string at these frequencies?
5. What is the speed of travel of the waves along the string?
**Hints**
1. 15 Hz is the lowest frequency at which a standing wave is produced. What is the longest wave that can be fitted on the string with a node at each end?
2. 30 Hz will produce a wave of half the length of 15 Hz.
3. 45 Hz will produce a wave of one-third of the length of the 15 Hz wave.
4. You know the length of the string and you know the wavelength in relation to this length.
5. Use v = f .
**Practical advice**
These questions are closely related to activities concerning standing waves on strings.
**Answers and worked solutions**
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**External reference**
This activity is taken from Advancing Physics chapter 6, 90S |