Transcript waves & sound study guide

WAVES & SOUND STUDY GUIDE
1. Frequency times wavelength equals_________.
Speed
2. Then number of complete wave cycles per unit time is called?
Frequency
3. A ____________ is a region in the medium in which
molecules are crowded together.
Compression
4. The ability of an object to vibrate by absorbing energy at its
natural frequency is called _________?
Resonance
5. The human perception of intensity is known as _________?
Loudness
6. Sound waves are this kind of wave _________?
Compressional waves
7. The speed of sound depends on?
Temperature
Density
Elasticity
8. Reflection of a wave occurs when the wave?
Strikes a boundary and bounces back
9. The pitch of a sound depends on its?
Frequency
8. Amplitude is related to ?
Wave energy
9. The loudness of a sound depends on?
Amplitude
10. Refraction occurs because waves?
Move at different speeds in different mediums
11. In rarefaction, the molecules of the medium are ?
Spaced apart
12. A wave in which the particles of the medium move at right
angles to the direction of the wave is called?
Transverse wave
13. You can hear a sound that is produced out of sight around
the corner of a building because of ?
Diffraction
13. The maximum displacement of molecules in a medium from
their rest position is called?
Amplitude
14. High pitch is produced by sounds that have?
High frequency
15. The ability of two or more waves to combine to form a new
wave is __________ __________?
Constructive interference
16. Any substance through which a wave is transmitted is
called a ___________?
Medium
17. When part of the Earth’s crust breaks, __________ waves
pass through the Earth.
Seismic
18. Sound travels the best and fastest through?
Solids
19. For the speed of a wave to remain constant, an increase in
wavelength requires a corresponding _________?
Decrease in frequency
20. All waves _________?
Can transfer energy, but not matter
21.In a standing wave the point at which the medium doesn’t
move is called the __________?
Node
22. Sounds with frequencies under 20Hz are __________
Infrasonic
23. The change in pitch of a sound caused by motion of either
the sound source or receiver is called _?
Doppler Effect
24. A wave in which the motion of the medium is parallel to
the direction of the wave is called a ?
Compressional wave
25. Finding objects by emitting sound waves and interpreting
the reflected sound is known as ________?
Echolocation
26. Sounds with frequencies above 20,000 HZ are?
Ultrasonic waves
27. A ______ is a region in the medium in which molecules are
crowded together?
Compression
28. _________ is used to locate objects underwater by the
reflection of sound waves?
Sonar
29. Can you sound in space? Why or why not?
No, because sound needs a medium to travel through.
30. What is acoustics?
The study of sound
31. What is reverberation?
The echoing effect produced by many reflections of sound.
32. How would you get rid of the echoes to enhance a sound
system for a musical production?
Add acoustic panels or carpets and drapes that will reduce
reflection and decrease the echo effect
33. Compare and contrast transverse and compressional
waves.
Both have wavelength, frequency, amplitude, crests and troughs.
Transverse waves do not require a medium, particles move at
right angels to the medium, light
Compressional- Mechanical waves, particles move parallel
to the medium, sound
34. How does density affect the speed of sound?
Low density-speed is fast
High density-slow speed
35. How does temperature affect the speed of sound?
Low temperature-slow speed
High temperature-high speed
36. How does elasticity affect the speed of sound?
Low elasticity-slow speed
High elasticity-fast speed
37. Draw and label a transverse wave
G-resting point; E-trough; F-crest; C-amplitude; D-wavelength
38. What is the speed of a wave if the frequency is 300 Hz
and the wavelength is 150m?
S = λf
S = (150)(300) = 45000 m/s
39. What is the wavelength of a 350 Hz wave traveling at
500m/s?
S = λf
λ = 1.4 meters
40. How many cycles per second would be characteristic of a
30 m wave traveling at 300 m/s?
S = λf
10 cycles/sec (Hz)