Question

A sound wave of wavelength 80 cm in glass enters into the air. If the velocities of
sound in glass and air are 5600 m/s and 340 m/s, calculate the wavelength of sound
in air.​

Answer 1

wavelength of sound in air is 4.8 cm

It has given that a sound wave of wavelength 80 cm in glass enters into the air. the velocities of sound in glass and air are 5600 m/s and 340 m/s respectively.

we have to find the wavelength of sound in air.

using formula, v = ηλ

where v is velocity, η is frequency and λ is wavelength.

as frequency remains constant.

v is directly proportional to wavelength.

so, v₁/v₂ = λ₁/λ₂

here, v₁ = 5600 m/s, λ₁ = 80 cm = 0.8 m

v₂ = 340 m/s, λ₂ = ?

so, 5600/340 = 0.8/λ₂

⇒λ₂ = 340 × 0.8/5600 = 0.048 m ≈ 4.8 cm

therefore wavelength of sound in air is 4.8 cm

Answer 2

Answer:

using formula, v = ηλ

where v is velocity, η is frequency and λ is wavelength.

as frequency remains constant.

v is directly proportional to wavelength.

so, v₁/v₂ = λ₁/λ₂

here, v₁ = 5600 m/s, λ₁ = 80 cm = 0.8 m

v₂ = 340 m/s, λ₂ = ?

so, 5600/340 = 0.8/λ₂

⇒λ₂ = 340 × 0.8/5600 = 0.048 m ≈ 4.8 cm