Question 1 Report
Fig. 1.1 shows how the displacement of the air particles varies with distance for a sound wave in air at one instant. What is the wavelength of this sound wave?
The correct answer is 20 cm. The wavelength is the distance for one complete cycle of the wave, and the graph completes one full wave between 0 cm and 20 cm before repeating. Reading 40 cm counts two whole waves, and 10 cm is only half a wave, so both are wrong.
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