Sound Waves — Prelims Questions

A source of sound emits waves of frequency $500,\text{Hz}$. It moves towards a stationary observer with a speed of $30,\text{m/s}$. The speed of sound in air is $340,\text{m/s}$. What is the apparent frequency heard by the observer?

An open organ pipe of length $L$ resonates at its fundamental frequency. If the speed of sound in air is $v$, what is the wavelength of the sound produced?

Two tuning forks A and B produce $4$ beats per second when sounded together. Tuning fork A has a frequency of $256,\text{Hz}$. When the prongs of tuning fork B are filed slightly, the beat frequency decreases to $2$ beats per second. What was the original frequency of tuning fork B?

A closed organ pipe of length $20,\text{cm}$ is resonating in its fundamental mode. If the speed of sound in air is $340,\text{m/s}$, what is the frequency of the sound produced?

Which of the following properties of sound waves remains constant when sound travels from air to water?

The intensity of sound from a point source is $10^{-8},\text{W/m}^2$ at a distance of $10,\text{m}$. What will be the intensity at a distance of $100,\text{m}$ from the source?

A sound wave has a frequency of $2,\text{kHz}$ and a wavelength of $35,\text{cm}$. How long will it take for the wave to travel a distance of $1.5,\text{km}$?