When the wavelength of sound changes from 1 m to 1.01 m, the number of beats heard are 4. The velocity of sound is
Options
(a) 400 m/s
(b) 300 m/s
(c) 404 m/s
(d) 100 m/s
Correct Answer:
404 m/s
Explanation:
v = ʋλ ⇒ Now, v = ʋ × 1
v = 1.01 × ʋ’ Also ʋ’ = (ʋ – 4)
So, ʋ × 1 = 1.01 × (ʋ – 4)
⇒ 1.01ʋ – ʋ = 1.01 × 4
0.01ʋ = 1.01 × 4
⇒ ʋ = 404 Hz
v = ʋλ
= 404 × 1 = 404 m/s