The graphical representation of two sound waves A and B propagating at the same speed. Class 9

The graphical representation of two sound waves A and B propagating at the same speed. Class 9

Question 1.

The graphical representation of two sound waves A and B propagating at the same speed of 345 m s^-1 is shown in Fig. What is the wavelength of each of them? Also, calculate their frequencies. Class 9

Answer:

From Fig. (x-axis up to 5.0 cm):

Wave A (blue curve): One complete wave spans approximately 5.0 cm.

1. λ_A = 5.0 cm = 0.05 m
2. v_A = v/λ = 345 / 0.05 = 6900 Hz

Wave B (red curve): One complete wave spans approximately 2.5 cm.

1. λ_B = 2.5 cm = 0.025 m
2. v_B = v/λ = 345 / 0.025 = 13800 Hz