Review Questions: Waves and Sound
a. vibration.
b. wave.
c. both.
d. neither.
2. The origin of any wave motion is
a. a condensation
b. velocity
c. a vibration
d. the wavelength
3. Unlike a transverse wave, a longitudinal wave has
a. no amplitude.
b. no frequency.
c. no wavelength.
d. no speed.
e. ...a longitudinal wave has all of these.
4. The period of a wave is defined to be
a. the time for one complete oscillation
b. the number of oscillations per second
c. the speed of propagation of the wave
d. the distance traveled in one cycle
5. Which of the following is not a transverse wave?
a. sound
b. light
c. radio
d. all of these
e. none of these
Reasoning: Sound is a longitudinal wave.
6. 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 101,000,000
Reasoning: MHz means million cycles per second. Thus 101 MHz is 101 million cycles per second.
7. 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 these.
Reasoning: Use the relationship: wavelength = speed/frequency = 300,000,000 m/s / 100,000,000 = 3 m.
8. If the frequency of a certain wave is 10 Hz, its period is
a. 0.1 seconds.
b. 10 seconds.
c. 100 seconds.
d. none of these.
9. A 60-vibration-per-second wave travels 30 meters in 1 second. Its frequency is
a. 30 hertz and it travels at 60 m/s.
b. 60 hertz and it travels at 30 m/s.
c. neither of these.
10. A weight or mass on the end of a spring bobs up and down one complete cycle every two seconds. Its frequency is
a. 0.5 hertz.
b. 2 hertz.
c. neither of these.
Reasoning: frequency = 1/period = 1/2 = 0.5 Hz
11. To say that one wave is out of phase with another is to say that the waves are
a. of different amplitudes.
b. of different frequencies.
c. of different wavelengths.
d. out of step.
d. all of these.
12. Wave interference occurs for
a. sound waves.
b. light waves.
c. water waves.
d. all of these.
e. none of these.
13. A standing wave occurs when
a. two waves overlap.
b. a wave reflects upon itself.
c. the speed of the wave is zero or near zero.
d. the amplitude of a wave exceeds its wavelength.
Reasoning: See page 370 of the textbook.
14. The Doppler effect is characteristic of
a. water waves.
b. sound waves.
c. light waves.
d. all of these.
e. none of these.
15. A Doppler effect occurs when a source of sound moves
a. towards you.
b. away from you.
c. both of these.
d. none of these.
16. An observer on the ground hears a sonic boom which is created by an 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. all of these.
e. none of these.
17. An aircraft that flies faster than the speed of sound is said to be
a. subsonic.
b. supersonic.
c. neither of these.
18. The frequency of the second hand on a clock is
a. 1 hertz.
b. 1/60 hertz.
c. 60 hertz.
19. The sonic boom at ground level produced by an aircraft will be reduced if the aircraft
a. is smaller.
b. flies higher.
c. is more streamlined.
d. all of these.
e. none of these.
20. If at a concert, a wind blows directly from the orchestra toward you, the frequency of the sound you hear will be
a. decreased.
b. increased.
c. neither decreased nor increased.
21. If at a concert, a wind blows directly from the orchestra toward you, the speed of the sound you hear will be
a. decreased.
b. increased.
c. neither decreased nor increased.
22. A wave travels an average distance of 1 meter in 1 second with a frequency of 1 Hz. Its amplitude is
a. less than 1 meter.
b. 1 meter.
c. more than 1 meter.
d. not enough information to say.
23. Sound travels through the air in the form of
a. transverse waves,
b. longitudinal waves,
24. and radio signals travel through the air in the form of
a. transverse waves.
b. longitudinal waves.
25. Pitch corresponds to
a. frequency,
b. noise,
c. loudness,
26. whereas amplitude corresponds to
a. frequency.
b. noise.
c. loudness.
27. A vibrating tuning fork causes an identical fork nearby to vibrate. This is called
a. refraction.
b. resonance.
c. beats.
d. reverberation.
Reasoning: See page 389 of the textbook for more information.
28. For this to happen, both forks must have the same (or multiple)
a. intensities.
b. amplitudes.
c. frequencies.
d. geometries.
e. all of these.
29. Which wave has the greatest period of oscillation?
a. Wave I
b. Wave II
c. Wave III
d. Wave IV
30. If the waves of the previous question have the same frequency, which is going by with the greatest speed?
a. Wave I
b. Wave II
c. Wave III
d. Wave IV
e. all have the same speed
31. If these are sound waves, which corresponds to the highest pitch?
a. Wave I
b. Wave II
c. Wave III
d. Wave IV
32. And which has the greatest wavelength?
a. Wave I
b. Wave II
c. Wave III
d. Wave IV
e. all have the same wavelength
33. Compared to a soft sound, the speed of a loud sound is
a. less,
b. greater,
c. the same,
34. and compared to low-frequency sound, higher-frequency sound travels
a. slower.
b. faster.
c. the same.
35. If the handle of a tuning fork is held solidly against a table, the resulting sound is
a. louder,
b. softer,
c. ... doesn't change,
36. and as a result of this, the length of time the fork keeps vibrating
a. increases.
b. decreases.
c. ... doesn't change.
37. When a source of sound approaches, measurements will show an increase in the sound's
a. speed,
b. frequency,
c. wavelength,
d. all of these,
e. none of these,
38. and when a source of sound recedes, measurements will show an increase in the sound's
a. speed.
b. frequency.
c. wavelength.
d. all of these.
e. none of these.
Reasoning: When receding, the frequency will be lower. This corresponds to a longer wavelength.
39. Which of the following aircraft will generate a shock wave? An aircraft traveling at
a. half the speed of sound.
b. exactly the speed of sound.
c. twice the speed of sound.
d. ... all of these.
40. The intensity of the sonic boom depends on the
a. speed of the aircraft.
b. size of the aircraft.
c. distance from the aircraft.
d. all of the above.
e. none of the above.