Chapter 13 Practice Physics Test Holt Physics

1. Which of the following is the region of a longitudinal wave in which the density and pressure are greater than normal?

a) rarefaction

b) compression

c) spherical area

d) Doppler area

2. How high or low we perceive a sound to be, depending on the frequency of the sound wave, is defined as the

a) infrasonic wave

b) frequency

c) ultrasonic wave

d) pitch

e) intensity

3. Which of the following has a higher speed of sound?

a) helium at 0C

b) air at 0C

c) copper at 0C

d) air at 100C

4. As a train starts from rest then accelerates down the track, coming toward an observer faster and faster, the frequency of the sound waves coming toward the observer will be

a) less than the source frequency

b) constant

c) stationary

d) greater than the source frequency

5. The Doppler effect occurs with

a) only sound waves

b) only compressional waves

c) only water waves

d) all waves

6.  As a sound  source approaches and then moves past a stationary observer, the observer will hear

a) a steady rise in pitch

b) a steady drop in pitch

c) a rise in pitch, then a drop in pitch

d) a drop in pitch, then a rise in pitch

7. The property of sound called intensity is

a) proportional to the rate at which sound energy flows through an area normal to the direction of propagation

b) inversely proportional to the rate at which sound energy flows through an area normal to the direction of propagation

c) proportional to the period of a sound wave

d) proportional to the frequency of a sound wave

8. Tripling the distance from a sound source will change the intensity of the sound waves by what factor?

a) 1/9

b) 1/3

c) 3

d) 9

9. What is the intensity of sound waves produced by a trumpet at a distance of 1.6m when the power output of the trumpet is 0.30W?

a) 5.9 x 10-3 W/m2

b) 1.5 x 10-2 W/m2

c) 9.3 x 10-3 W/m2

d) 3.7 x 10-2 W/m2

10. If the intensity of a sound is increased by a factor of 100, the new decibel level will be

a) two units greater

b) double the old one

c) 10 times greater

d) 20 units greater

11. A difference in 10 dB means the sound is

a) twice as loud

b) 10 times as loud

c) 100 times as loud

d) there would be no change in loudness

12. The intensity at a distance of 6.0 m from a source that is radiating equally in all directions is 6.0 x 10-10 W/m2.  What is the intensity level in dB?

a) 18 dB

b) 23 dB

c) 28 dB

d) 32 dB

13. Which of the following is the condition that exists when the frequency of a force applied to a system matches the natural frequency of vibration of the system?

a) pitch

b) decibel level

c) timbre

d) beats

e) resonance

14. If both ends of a pipe are open,

a) all harmonics are present

b) no harmonics are present

c) odd harmonics are present

d) even harmonics are present

15. What is the lowest frequency that will resonate in a 2.0 m length organ pipe closed at one end if the temperature of the air is 15C?

a) 42 Hz

b) 85 Hz

c) 170 Hz

d) 680 Hz

16. If a guitar string has a fundamental frequency of 500 Hz, what is the frequency of its second harmonic?

a) 250 Hz

b) 750 Hz

c) 1000 Hz

d) 1500 Hz

17. The effects of sound on the ear are loudness, pitch, and quality.  Loudness is an effect of _____, pitch is an effect of _____, and timbre is an effect of _____.

a) intensity; harmonic content; frequency

b) harmonic content; frequency; intensity

c) frequency; intensity; harmonic content

d) intensity; frequency; harmonic content

18.  What phenomenon is created by two tuning forks side by side that emit frequencies that differ by only a small amount?

a) resonance

b) interference

c) the Doppler effect

d) beats

19.  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 216 Hz and 224 Hz, respectively?

a) 6 Hz

b) 8 Hz

c) 9 Hz

d) 3 Hz

e) 220 Hz

20.  At a distance of 15 m from a sound source the intensity level is 60 dB.  What is the intensity level at a point 2.0 m from the source?  Assume that the source radiates equally in all directions.

a) 55.7 dB

b) 57.5 dB

c) 75.5 dB

d) 77.5 dB

21.  A train is traveling toward you at 120 km/hr.  The train blows its 400 Hz whistle.  Take the speed of sound to b 340 m/s.  What frequency do you hear?

a) 444 Hz

b) 439 Hz

c) 364 Hz

d) 361 Hz

e) 354 Hz

22.  Sound waves cannot travel in

a) air

b) water

c) steel

d) a vacuum

e) Sound can travel in all of the above

23.  A sonic boom is created by and airplane flying at a speed

a) just below the speed of sound

b) equal to the speed of sound

c) greater than the speed of sound

d) None of the above

----------Key----------

1. (b)

2. (d)

3. (c)

4. (b)

5. (d)

6. (c)

7. (a)

8. (a)

9. (c)

10. (d)

11. (a)

12. (c)

13. (e)

14. (a)

15. (a)

16. (c)

17. (d)

18. (d)

19. (b)

20. (d)

21. (a)

22. (d)

23. (c)