Chapter 17 test
The higher-frequency sound human ears can usually hear is about....
20,000 Hz
Which of the following variables can affect the wavelength of a sound wave? I. the medium II. the frequency of the wave III. the amplitude of the wave
I only (the medium)
The height of a wave crest is called....
amplitude
Explain why a fire engine's siren sounds lower in pitch after the fire engine passes you.
as its going away from you the frequency gets lower
In a transverse wave, the medium vibrates....
at right angles to the wave direction
What causes refraction of a wave as it enters a new medium at an angle?
because one side of the wave moves more slowly than the other side due to density
Why does a node in a standing wave have zero displacement?
because there is a destructive interference between the incoming and reflected waves
Regardless of the direction of waves far from an island, waves close to the island move toward the shore on all sides.
because they are bent at different depths of the water, like a new medium
Name two kinds of longitudinal waves and explain how you know they are longitudinal.
compression and P-waves; because you can see the compression and rarefractions
When a wave bends around an obstacle, it is called....
diffraction
For waves moving at a constant speed, if wavelength is doubled, then frequency is...
halved
What are the names of the three small bones in the middle ear, and what is their purpose?
hammer, anvil, and stirrup; they amplify the motion or the eardrum
How is intensity different from loudness?
intensity is the energy of the wave and loudness is the perception of hearing
When a wave is reflected, its speed
is unchanged
A large speaker is better than a small speaker for producing sounds with...
low frequency
which of the following is required to transmit energy using mechanical waves?
medium
When two waves interfere, the displacement where two troughs meet is.....
negative
which conditions best describe what happens when a transverse wave is reflected?
some of the wave does not pass through a boundary or surface.
Which of the following statements is generally true for the musical instrument (panpipes) below?
the shortest has the highest pitch
Ocean waves flow past a concrete support for a bridge. The support is 30 meters wide and it sits in very deep water. Which of the following is LEAST likely to occur?
the waves will diffract
which of the following is Not true about mechanical waves?
they transfer matter
Why are the materials uses in construction of a concert hall important?
to eliminate dead spot
Sonar can make use of....
ultrasound
What is the function of the eardrum?
vibrations of the outer ear become sound waves in the inner ear
How are wavelength and frequency related for a wave moving at constant speed?
wavelength is inversely proportional to frequency.