Gelombang Bunyi • Part 4: Soal Sumber Bunyi (Dawai, Pipa Organa Terbuka & Tertutup)

Introduction

This tutorial provides a step-by-step guide to understanding sound waves, specifically focusing on examples of sound frequency from the YouTube video "Gelombang Bunyi • Part 4: Soal Sumber Bunyi." The tutorial covers calculating the fundamental frequencies of strings and organ pipes, as well as determining mass in a Melde experiment and comparing wavelengths of open and closed organ pipes.

Step 1: Determine the Fundamental Frequency of a String

To find the fundamental frequency and harmonics of a string (dawai), follow these steps:

1. Identify the parameters:

   • Length of the string (L)
   • Tension (T)
   • Mass per unit length (μ)

2. Apply the formula for the fundamental frequency (f1): [ f_1 = \frac{1}{2L} \sqrt{\frac{T}{\mu}} ]

3. Calculate the frequency:

   • Plug in the values for T and μ to compute the frequency.

4. Subsequent harmonics:

   • For the second harmonic (f2), use: [ f_2 = 2f_1 ]
   • For the third harmonic (f3), use: [ f_3 = 3f_1 ]

Practical Tip

Ensure that the string is under uniform tension and measure its length accurately to achieve precise results.

Step 2: Determine Frequencies of Open and Closed Organ Pipes

To find the fundamental frequency and second harmonic of both open and closed organ pipes, follow these steps:

1. Identify the parameters:

   • Length of the pipe (L)
   • Speed of sound in air (v) which is approximately 343 m/s at room temperature.

2. Apply the formulas:

   • For an open pipe: [ f_n = \frac{n \cdot v}{2L} \quad (n = 1, 2, 3, \ldots) ]
   • For a closed pipe: [ f_n = \frac{n \cdot v}{4L} \quad (n = 1, 3, 5, \ldots) ]

3. Calculate the frequencies:

   • Use the formulas to calculate the fundamental frequency and the second harmonic for both types of pipes.

Common Pitfall

Remember that closed pipes only produce odd harmonics, while open pipes can produce both odd and even harmonics.

Step 3: Determine Mass in a Melde Experiment

To find the mass used in a Melde experiment, follow these steps:

1. Understand the setup:

   • The Melde experiment involves a vibrating string and a mass hanging from it.

2. Measure the frequency of the standing wave:

   • Use a frequency measurement tool to determine the frequency (f) of the vibrating string.

3. Use the formula: [ m = \frac{4L^2T}{f^2} ]

   • Here, T is the tension in the string and L is its length.

Practical Tip

Make sure to measure the frequency accurately, as this will directly affect your mass calculation.

Step 4: Compare Wavelengths of Open and Closed Organ Pipes

To compare the wavelengths produced by open and closed organ pipes, follow these steps:

1. Use the frequency calculations from Step 2.

2. Apply the wavelength formulas:

   • For an open pipe: [ \lambda = \frac{v}{f} ]
   • For a closed pipe: [ \lambda = \frac{v}{f} ]

3. Calculate the wavelengths:

   • Calculate and compare the wavelengths for both types of pipes using their respective frequencies.

Conclusion

This tutorial has guided you through calculating sound frequencies for strings and organ pipes, determining mass in a Melde experiment, and comparing the wavelengths created by open and closed organ pipes. For further learning, consider reviewing related materials on sound waves or exploring additional videos in the series.