Q117 / 150 · MHT CET 2021 (24 Sep Shift 1) · Physics
The frequency of a tuning fork is $220 \mathrm{~Hz}$ and the velocity of sound in air is $330 \mathrm{~m} / \mathrm{s}$. When the tuning fork completes 80 vibrations, the distance travelled is
- Correct answerA$120 \mathrm{~m}$
- B$60 \mathrm{~m}$
- C$53 \mathrm{~m}$
- D$100 \mathrm{~m}$
Solution
$$
\begin{aligned}
& \mathrm{f}=220 \mathrm{~Hz}, v=330 \mathrm{~m} / \mathrm{s} \\
& v=\mathrm{f} \lambda \\
& \lambda=\frac{\mathrm{v}}{\mathrm{f}}=\frac{330}{220}=\frac{3}{2} \mathrm{~m}
\end{aligned}
$$
Distance travel in 80 vibrations
$$
=80 \times \frac{3}{2}=120 \mathrm{~m}
$$
Hence, the correct answer is option: 'A'.