Question

Sound waves of wave length 1.5 cm have velocity of 350m/s in air. What is their frequency? Can this sound be heard by the human ear?

Answer 1

Answer : -

Given that,

Wave length $(\lambda)$ = 1.5 cm

Velocity = 350 m/s

To find,

Frequency $(\nu)$

Wave length in metres = $\frac{1.5}{100}$

Wave length in metres = 0.015 m

Frequency $(\nu) = v \times \lambda$

Frequency $(\nu) = 350 \times 0.015$

Frequency $(\nu)$ = 5.25 Hz

No, it can't be heard by humans as the hearing range of a human ear is from 20 Hz - 20,000 Hz (20 kHz).

But here, the frequency is below than 20 Hz. So, humans cannot hear this sound.