The graphical representation of two sound waves A and B propagating at the same speed of 345 ms⁻¹ is shown in the given figure. What is the wavelength of each of them? Also, calculate their frequencies.

Wave A completes one full wave in 2.5 cm.

Therefore, wavelength of A,

$$\lambda_A = 2.5 \text{ cm} = 0.025 \text{ m}$$

Wave B completes one full wave in 5 cm.

Therefore, wavelength of B,

$$\lambda_B = 5 \text{ cm} = 0.05 \text{ m}$$

Speed of sound, v = 345 ms⁻¹

Using the relation: v = vλ

Frequency of wave A:

$$v_A = \frac{345}{0.025}$$

$$v_A = 13800 \text{ Hz}$$

Frequency of wave B:

$$v_B = \frac{345}{0.05}$$

$$v_B = 6900 \text{ Hz}$$