91Ó°ÊÓ

In an experiment to determine the speed of sound, two observers, \(\mathrm{A}\) and \(\mathrm{B}\), were stationed \(5.00 \mathrm{~km}\) apart. Each was equipped with a gun and a stopwatch. Observer-A heard the report of B's gun \(15.5 \mathrm{~s}\) after seeing its flash. Later, A fired his gun and \(\mathrm{B}\) heard the report \(14.5 \mathrm{~s}\) after seeing the flash. Determine the speed of sound and the component of the speed of the wind along the line joining \(\mathrm{A}\) to \(\mathrm{B}\).

A disk has 40 holes around its circumference and is rotating at \(1200 \mathrm{rpm}\). Determine the frequency and wavelength of the tone produced by the disk when a jet of air is blown against it. The temperature is \(15^{\circ} \mathrm{C}\).

Determine the speed of sound in carbon diaxide \((M-44 \mathrm{~kg} / \mathrm{kmol}, \gamma=1.30)\) at a pressure of \(0.50 \mathrm{~atm}\) and a temperature of \(400^{\circ} \mathrm{C}\).

At S.T.P., the speed of sound in air is \(331 \mathrm{~m} / \mathrm{s}\). Determine the speed of sound in hydrogen at S.T.P. if the specific gravity of hydrogen relative to air is \(0.0690\) and if \(\gamma=1.40\) for both gases.

Find the speed of compression waves in a metal rod if the material of the rod has a Young's modulus of \(1.20 \times 10^{10} \mathrm{~N} / \mathrm{m}^{2}\) and a density of \(8920 \mathrm{~kg} / \mathrm{m}^{3}\).

An increase in pressure of \(100 \mathrm{kPa}\) causes a certain volume of water to decrease by \(5 \times 10^{-3}\) percent of its original volume. ( \(a\) ) What is the bulk modulus of water? (b) What is the speed of sound (compression waves) in water?

A sound has an intensity of \(5.0 \times 10^{-7} \mathrm{~W} / \mathrm{m}^{2}\). What is its intensity level?

A person riding a power mower may be subjected to a sound of intensity \(2.00 \times 10^{-2} \mathrm{~W} / \mathrm{m}^{2}\). What is the intensity level to which the person is subjected?

A rock band might easily produce a sound level of \(107 \mathrm{~dB}\) in a room. To two significant figures, what is the sound intensity at \(107 \mathrm{~dB}\) ?

A whisper has an intensity level of about \(15 \mathrm{~dB}\). What is the corresponding intensity of the sound?