AQA GCSE FOUNDATION Physics: Investigating Waves in a Solid

Investigating Waves in a Solid: A Tutorial

This tutorial will guide you through an investigation of wave properties using a stretched string. You will learn how to measure wave frequency, speed, and wavelength, and explore the relationship between these properties and the medium (string tension).

Materials:

• Vibration Generator
• Stretched String (e.g., fishing line)
• Ruler
• Stopwatch
• Weights (for adjusting tension)

Procedure:

1. Set Up: Attach one end of the string to the vibration generator and the other end to a fixed point. Ensure the string is taut.
2. Adjust Tension: Use weights to adjust the tension in the string. Record the tension applied.
3. Generate Waves: Turn on the vibration generator. Observe the waves travelling along the string.
4. Measure Wavelength:
   • Identify two consecutive crests or troughs in the wave pattern.
   • Measure the distance between these points using a ruler. This is the wavelength (?).
5. Measure Frequency:
   • Use a stopwatch to time the number of waves passing a fixed point in a given time period.
   • Divide the number of waves by the time to obtain the frequency (f).
6. Calculate Wave Speed: Use the formula:
   • v = f * ?
   • Where:
     • v = wave speed
     • f = frequency
     • ? = wavelength

Experimentation:

1. Varying Tension: Repeat steps 2-6 with different tensions applied to the string. Record the values for frequency, wavelength, and wave speed for each tension.
2. Analyzing Results:
   • Plot a graph of wave speed against tension. What is the relationship between the two?
   • Compare the frequencies and wavelengths for different tensions. What observations can you make?

Conclusion:

• Summarize your findings about the relationship between wave speed, frequency, wavelength, and tension.
• Discuss the implications of these findings for the transmission of waves through different mediums.

Further Exploration:

• Investigate the effects of different string materials (e.g., different thicknesses, densities) on wave properties.
• Explore the concept of resonance and how it relates to wave properties.

Safety Precautions:

• Ensure that the vibration generator is switched off when not in use.
• Handle the weights carefully and avoid dropping them on your feet.
• Be cautious of the vibrating string, as it may be moving at a high speed.