Question

Two closed pipes having lengths 0.50m and 0.49m contain a gas at the same temperature set into vibrations in their fundamental frequency. 3 beats per second were heard between them. Calculate the velocity of sound contained in the pipes.

• A. 325 m/s
• B. 375 m/s
• C. 350 m/s
• D. 300 m/s

Answer 1

The correct option is D 300 m/s

$f_1=\frac{v}{4l_1}=\frac{v}{4\times 0.5}=\frac{v}{2}Hz=0.5vHz$
$f_2=\frac{v}{4l_2}=\frac{v}{4\times 0.49}=0.51vHz$
$f_2-f_1=3$
$0.51v-0.5v=3$
$0.01v=3$
$v=300m{s}^{-1}$

Ans: $300m{s}^{-1}$