Q&A Hero

Q: Resonance occurs when a 200-Hz tuning fork encounters a sound wave with a frequency of A) 150 Hz. B) 200 Hz. C) 300 Hz. D) any of the above E) none of the above

Q: When the handle of a tuning fork is held solidly against a table, the time the fork keeps vibrating becomes A) longer. B) shorter. C) remains the same

Q: Sound will be louder when a struck tuning fork is held A) in the air. B) with its base against a tabletop. C) with its prongs in shallow water. D) in your closed fist.

Q: You slowly rub your wet finger around the thin rim of a wine glass while you hold its base firmly to a tabletop with your other hand. The resulting sounds illustrates A) forced vibrations. B) resonance. C) both of these D) none of the above

Q: Resonance can be viewed as forced vibration with the A) least amount of energy input. B) maximum amount of energy input. C) matching of wave amplitudes. D) matching of constructive and destructive interference. E) minimum beat frequency.

Q: The least energy required to produce forced vibrations in an object occurs A) below its natural frequency. B) at its natural frequency. C) above its natural frequency. D) none of the above

Q: Troops break step when marching across a bridge to prevent A) interference. B) resonance. C) wave motion. D) frequency distortion.

Q: Some singers are able to shatter a crystal chandelier with their voice, which illustrates A) an echo. B) sound refraction. C) beats. D) resonance. E) interference.

Q: A bass fiddle is louder than a harp because of its A) thicker strings. B) sounding board. C) lower pitch. D) all of the above E) none of the above

Q: "Sympathetic vibrations" refers to A) beats. B) interference. C) pitch. D) resonance.

Q: The object with a natural frequency of higher pitch is a A) small bell. B) large bell. C) either of these D) none of the above

Q: The natural frequency of an object depends on its A) elasticity. B) size and shape. C) both of these D) none of the above

Q: A bat chirps to locate a tasty lunch. The chirp travels at 340 m/s and its echo is heard 1 s after the chirp. Distance to the lunch is A) 85 m. B) 170 m. C) 340 m.

Q: Ultrasonic sound that travels at 1530 m/s in ocean water is bounced off the ocean floor and returns to the ship above. If the round trip takes 3 s, the depth of the water is A) 1530 m. B) 2295 m. C) 3060 m. D) 4590 m.

Q: An acoustical engineer designing a music hall is most concerned with A) modulation. B) forced vibrations. C) resonance. D) beats. E) reverberations.

Q: Sound energy that is not reflected is A) transmitted. B) absorbed. C) either or both of these

Q: A dolphin perceives its environment by the sense of A) sight. B) sound. C) both of these D) none of the above

Q: Sound refraction depends on the speed of sound being A) constant. B) variable. C) proportional to frequency. D) inversely proportional to wavelength. E) none of the above

Q: On days when the air nearest the ground is colder than air above, sound waves tend to A) be refracted upward. B) be refracted downward. C) travel without refraction.

Q: When sound travels faster higher in the air than it does closer to the ground, sound bends A) upward. B) downward. C) neither of these

Q: When sound travels faster at ground level than higher in the air, sound tends to bend A) upward. B) downward. C) neither of these

Q: Refraction of sound can occur in A) air. B) water. C) both of these D) none of the above

Q: The explanation for all types of refraction involves a change in A) frequency. B) period. C) speed. D) all of the above E) none of the above

Q: Reverberation is a phenomenon you would be likely experience while singing in the A) shower. B) desert. C) tundra.

Q: Reverberation is a case of A) sound interference. B) forced vibrations. C) re-echoed sound. D) resonance. E) none of the above

Q: The reflection of sound is A) reverberation. B) an echo. C) a rare occurrence.

Q: A general rule for estimating the distance in kilometers between an observer and a lightning bolt is to count the number of seconds between seeing the lightning and hearing it, and dividing by A) 2. B) 3. C) 4. D) 5. E) none of the above

Q: An explosion occurs 34 km away. For sound that travels at 340 m/s, you'll hear the explosion in A) 0.1 s. B) 1 s. C) 10 s. D) 20 s. E) more than 20 s.

Q: A 340-Hz sound wave travels at 340 m/s in air with a wavelength of A) 1 m. B) 10 m. C) 100 m. D) 1000 m. E) none of the above

Q: Loudness of sound is most closely related to A) frequency. B) wavelength. C) amplitude. D) speed.

Q: The speed of sound varies with A) loudness. B) frequency. C) wavelength. D) all of the above E) none of the above

Q: For each 1-degree increase in temperature above 0C, the speed of sound in air A) decreases by 0.6 m/s. B) increases by 0.6 m/s. C) as with the speed of light, doesn't change.

Q: Sound travels faster when the air is A) warm. B) cold. C) neither of these

Q: The speed of a sound wave in air depends on A) its frequency. B) its wavelength. C) the air temperature. D) all of the above E) none of the above

Q: Sound waves cannot travel in A) air. B) water. C) steel. D) a vacuum.

Q: Sound travels fastest in A) water vapor. B) water. C) ice. D) same in all

Q: Sound travels faster in A) air. B) water. C) steel. D) a vacuum. E) same in each

Q: Compressions and rarefactions of sound waves normally travel A) at different speeds. B) in opposite directions. C) at reduced frequencies. D) all of the above E) none of the above

Q: Ultrasonic sound waves have relatively A) low frequencies. B) long wavelengths. C) both of these D) none of the above

Q: Infrasonic sound waves have relatively A) low frequencies. B) long wavelengths. C) both of these D) none of the above

Q: Our ears are best at hearing A) infrasonic sound. B) ultrasonic sound. C) both of these D) none of the above

Q: The range of human hearing is about A) 10 Hz - 10,000 Hz. B) 20 Hz - 20,000 Hz. C) 40 Hz - 40,000 Hz. D) all of the above, depending on the person

Q: Double the frequency of sound and you also double its A) wavelength. B) speed. C) amplitude. D) all of the above E) none of the above

Q: A sound source of high frequency emits a high A) speed. B) amplitude. C) pitch. D) all of the above E) none of the above

Q: A sound wave is a A) longitudinal wave. B) transverse wave. C) standing wave. D) shock wave. E) none of the above

Q: The source of all sounds is something that is A) accelerating. B) moving. C) vibrating. D) undergoing simple harmonic motion.

Q: A compression is a squash and a rarefaction is a A) crunch. B) reverse tension. C) stretch.

Q: Compressions and rarefactions travel A) at right angles to the wave. B) in the same direction of the wave. C) in opposite directions of the wave. D) none of the above

Q: Compressions and rarefactions are characteristic of A) longitudinal waves. B) transverse waves. C) both of these D) none of the above

Q: The vibrations of a longitudinal wave move in a direction A) of wave travel. B) at right angles to the direction of wave travel. C) opposite to wave travel.

Q: The vibrations of a transverse wave move in a direction A) of wave travel. B) at right angles to the direction of wave travel. C) opposite to wave travel.

Q: Which of the following is a longitudinal wave? A) sound B) light C) radio D) all of the above E) none of the above

Q: Which of the following is not a transverse wave? A) sound B) light C) radio D) all of the above E) none of the above

Q: The compressions and rarefactions in a longitudinal wave travel in A) the same direction. B) opposite directions. C) neither of these

Q: A wave travels an average distance of 1 m in 1 s with a frequency of 1 Hz. Its amplitude is A) less than 1 m. B) 1 m. C) more than 1 m. D) not enough information

Q: A boat at anchor is rocked by waves whose crests are 40 m apart and with wave speed 10 m/s. These waves reach the boat once every A) 400 s. B) 30 s. C) 4 s. D) 0.25 s.

Q: A skipper on a boat notices wave crests passing the anchor chain every 5 s. The skipper estimates the distance between crests is 15 m. What is the speed of the water waves? A) 3 m/s B) 5 m/s C) 15 m/s D) not enough information

Q: A succession of 2-m long water waves on a lake goes by a piece of floating cork that bobs up and down one complete cycle each second. What is the speed of the wave? A) 0.25 m/s B) 0.50 m/s C) 1.0 m/s D) 2 m/s E) 4 m/s

Q: Radio waves travel at the speed of light, 300,000 km/s. The wavelength of a radio wave received at 100 MHz is A) 0.3 m. B) 3.0 m. C) 30 m. D) 300 m. E) none of the above

Q: During a single period, the distance traveled by a wave is A) one-half wavelength. B) one wavelength. C) two wavelengths. D) more information is needed

Q: Bree dips a pair of prongs onto a water surface and produces waves. When she dips more frequently the resulting waves A) have shorter wavelengths. B) remain the same in wavelength. C) have longer wavelengths. D) move faster. E) none of the above

Q: A floating leaf oscillates up and down twice in 1 s as a water wave of wavelength 10 m passes by. What is the wave's speed? A) 2 m/s B) 10 m/s C) 20 m/s D) 40 m/s E) more than 40 m/s

Q: A wave oscillates up and down twice in 1 s. If the wave travels an average distance of 6 m in 1 s, its wavelength is A) 0.5 m. B) 1 m. C) 2 m. D) 3 m. E) 6 m.

Q: A floating leaf oscillates up and down twice in 1 s as a water wave passes by. What is the wave's frequency? A) 0.5 Hz B) 1 Hz C) 2 Hz D) 3 Hz E) 6 Hz

Q: A wave travels an average distance of 6 m in 0.5 s. What is the wave's average velocity? A) less than 0.2 m/s B) 1 m/s C) 3 m/s D) 6 m/s E) more than 6 m/s

Q: A wave travels an average distance of 6 m in 1 s. What is the wave's average velocity? A) less than 0.2 m/s B) 1 m/s C) 3 m/s D) 6 m/s E) more than 6 m/s

Q: The medium in which a wave travels A) moves along with the wave. B) transmits the wave. C) inhibits the wave. D) reflects the wave.

Q: What moves from place to place in wave motion is A) energy. B) momentum. C) pressure. D) matter.

Q: The source of all wave motion is A) a wave pattern. B) a harmonic object. C) something vibrating. D) a region of variable high and low pressure. E) none of the above

Q: Wave speed and wave frequency are two terms that are A) basically the same. B) fundamentally different from each other. C) opposites. D) reciprocals.

Q: The period of the second hand on a clock is A) 1 s. B) 1/60 s. C) 60 s. D) 3600 s. E) 12 h.

Q: The frequency of the second hand on a clock is A) 1 Hz. B) 1/60 Hz. C) 60 Hz.

Q: A mass suspended from a spring bobs up and down one complete cycle every 2 s. Its period is A) 0.5 s. B) 1 s. C) 2 s. D) none of the above

Q: If you double the frequency of a vibrating object, its period A) doubles. B) is halved. C) is one-quarter.

Q: A mass on the end of a spring bobs up and down 1 complete cycle every 2 s. Its frequency is A) 0.5 Hz. B) 2 Hz. C) neither of these

Q: An electric razor in Europe completes 50 vibrations in 1 s. The frequency of these vibrations is A) 50 Hz with a period of 1/50 s. B) 1/50 Hz with a period of 50 s. C) 50 Hz with a period of 50 s. D) 1/50 Hz with a period of 1/50 s.

Q: A wave of 60 vibrations per second travels 30 m in 1 s. Its frequency is A) 30 Hz. B) 60 Hz. C) more than 60 Hz. D) none of the above

Q: If the frequency of a certain wave is 10 Hz, its period is A) 0.1 s. B) 10 s. C) 100 s. D) none of the above

Q: How many vibrations per second are associated with a 101-MHz radio wave? A) less than 101,000,000 B) 101,000,000 C) more than 101,000,00 D) none of the above

Q: A wave having a frequency of 1000 Hz vibrates at A) less than 1000 cycles per second. B) 1000 cycles per second. C) more than 1000 cycles per second. D) none of the above