Question

Two organ (open) pipes of lengths 50 cm and 51 cm produce 6 beats/s. Then the speed of sound is nearly

• A. 300 ms${}^{-1}$
• B. 306 ms${}^{-1}$
• C. 303 ms${}^{-1}$
• D. 350 ms${}^{-1}$

Answer 1

Answer: (B)

306 ms${}^{-1}$

$\delta =\frac{v}{2l}$

$Beat={\delta }_1-{\delta }_2$

$6=\frac{v}{2\left(50\right)}-\frac{v}{2\left(51\right)}$

$6=v(\frac{1}{2\times 50}-\frac{1}{2\times 51})$

$v=\frac{6\times 2\times 50\times 2\times 51}{2\times 51-2\times 50}$ $=30600cm/s$ $=306m/s$