Exam 14: Sound

When a sound wave moves through a medium such as air,the motion of the molecules of the medium is in what direction (with respect to the motion of the sound wave)?

If one-third of the members of a symphony orchestra are absent because of head colds,thus reducing the overall intensity of sound by 33%,what will be the reduction in the decibel level?

A tuning fork is sounded above a resonating tube (one end closed),which resonates at a length of 0.80 m and again at 1.40 m.What is the frequency of the fork when the speed of sound is taken to be 340 m/s?

Assuming that the wave speed varies little when sound waves are traveling through a material that suddenly changes density by 10%,what percentage of the incident wave intensity is reflected?

​A sound wave has a frequency of 850 Hz.What is the sound wave's wavelength if the air temperature is 26.0 ^$\circ$ C?

A string with fixed ends is made to go into standing wave patterns.At a given tension,the lowest frequency for which such a pattern exists is 150 Hz.Which of the following frequencies would also cause a standing wave pattern in this case?

A plane is traveling at Mach 0.930 through air at a temperature of 0°C.What is the plane's speed? (Speed of sound at 0°C is 331 m/s. )

Two loudspeakers are placed side by side and driven by the same source at 525 Hz.A listener is positioned in front of the two speakers and on the line separating them,thus creating a constructive interference at the listener's ear.If one of the speakers is gradually pushed toward the listener,how far must it be moved to repeat the condition of constructive interference at the listener's ear? (The speed of sound = 340 m/s. )

A tuning fork is sounded above a resonating tube (one end closed),which resonates at a length of 0.40 m and again at 1.2 m.If the tube length were extended further,at what point will the tuning fork again create a resonance condition?

For a standing wave in an air column in a pipe that is open at both ends,there must be at least

Comparing the speed of sound in liquids,gases,and solids,the speed of sound is usually lowest in ____ and highest in ____.

A flute behaves like a tube open at both ends.If its length is 67.0 cm,and the speed of sound is 340 m/s,what is its fundamental frequency in Hz?

In the afternoon,the decibel level of a busy freeway is 85 dB with 90 cars passing a given point every minute.Late at night,the traffic flow is only 8 cars per minute.What is the late-night decibel level?

An airplane flying with a constant speed flies from a warm air mass into a cold air mass.The Mach number will

A series of ocean waves,7.0 m between crests,move past at 4.0 waves/s.Find their speed.

Two vibrating tuning forks,held side by side,will create a beat frequency of what value if the individual frequencies of the two forks are 306 Hz and 300 Hz,respectively?

If a guitar string has a fundamental frequency of 512 Hz,what is the frequency of its first overtone?

Quadrupling the power output from a speaker emitting a single frequency will result in what increase in loudness?

A relatively new medical device that uses ultrasonics is referred to by the acronym CUSA.What does the letter A stand for?

What is the intensity level of a sound with intensity of 6.0 × 10−¹⁰ W/m²? ( I₀ = 10−¹² W/m² )