Suggested practical - measuring waves in a solid
Measure the frequency, wavelength and speed of waves in a solid
Jonny Nelson explains waves in a solid with a GCSE Physics practical experiment
There are many different ways that the speed of waves in a solid can be measured. One method involves the use of a vibration generator.
Aim of the experiment
To measure the frequency, wavelength and speed of waves in a string.
Method
- Attach a string or cord to a vibration generator and use a 200 gram (g) hanging mass and pulley to pull the string taut as shown in the diagram. Place a wooden bridge under the string near the pulley.
- Switch on the vibration generator and adjust the wooden bridge until stationary waves can be clearly observed.
- Measure the length of as many half wavelengths (loops) as possible, divide by the number of half wavelengths (loops). This is half the wavelength, doubling this gives the wavelength.
- The frequency is the frequency of the power supply.
- Calculate the speed of the waves using wave speed = frequency Ă— wavelength
Example results table
| Number of half wavelengths | Length of x half wavelengths (cm) | Wavelength (cm) | Frequency (Hz) | Wave speed (cm/s) |
| ... | ... | ... | ... | ... |
| Number of half wavelengths | ... |
|---|---|
| Length of x half wavelengths (cm) | ... |
| Wavelength (cm) | ... |
| Frequency (Hz) | ... |
| Wave speed (cm/s) | ... |
Risks/hazards
| Hazard | Consequence | Control measures |
| Cord snapping | Damage to eyes | Eye protection / safety screen |
| Hazard | Cord snapping |
|---|---|
| Consequence | Damage to eyes |
| Control measures | Eye protection / safety screen |