Question

The frequency of a tuning fork is $256Hz.$ The velocity of sound in air is $344m{s}^{-1}$. The distance travelled (in metres) by the sound during the time in which the tuning fork completes $32$ vibrations is:

• A. $21$
• B. $43$
• C. $86$
• D. $129$

Answer 1

Answer: (B)

$43$

Frequency is given as $f=256$ Hz

Time period of tuning fork $T=\frac{1}{f}$ $=\frac{1}{256}$

As $T$ is the time in which tuning fork will complete one vibration.

So, $32T$ is the time in which fork will complete $32$ vibrations.

$\therefore$ Time elapsed during 32 vibration $t=32T=32\times \frac{1}{256}$ $=\frac{1}{8}sec$

Distance traveled by sound during this time $d=Vt$ $=344\times \frac{1}{8}$

$⟹$ $d=43m$