chapter 7 physical science
Relative to the radio signals sent out by a spacecraft headed away from the earth, the signals that are received on the earth have
a lower frequency
The amplitude of a sound wave determines its
loudness
A 80-dB sound carries more energy than a 40-dB sound by a factor of
10,000
Ocean waves with a period is 10 s are found to have a wavelength of 120 m. Their speed is
12 m/s
The musical note A has a frequency of 440 Hz and its wavelength in seawater is 3.5 m. The speed of sound in seawater is
1540 m/s.
The speed of light in a transparent plastic whose index of refraction is 1.5 is
2 × 108 m/s.
Radio amateurs are permitted to communicate on the "10-meter band". What frequency of radio waves corresponds to a wavelength of 10 meters? The speed of radio waves is 3 × 108 m/s.
3.0 × 107 Hz
Two waves meet at a time when one has the instantaneous amplitude A and the other has the instantaneous amplitude B. Their combined amplitude at this time is
A+B
A frequency that is not an overtone of the fundamental frequency F is
F/2
When waves go from one place to another, they carry
energy
A converging lens of focal length f produces a real image of a real object when the object is
farther than f from the lens.
A sound wave whose frequency is 50 Hz
has a relatively long wavelength.
A changing electric field gives rise to
magnetic field
In an electromagnetic wave, the electric field is
perpendicular to both the magnetic field and the wave direction.
Which one of the following effects does not occur in all types of wave?
polarization
When the American flag is viewed with red light it appears
red and black
An example of a purely longitudinal wave is a
sound wave
Sound waves of frequency 300 Hz have a wavelength relative to sound waves in the same medium of frequency 600 Hz that is
twice as great
A medal in a plastic cube whose index of refraction is 1.5 appears to be 20 mm below the upper surface of the cube. The depth of the medal is actually
30mm
A boat at anchor is rocked by waves whose crests are 50 m apart and whose speed is 10 m/s. These waves reach the boat once every
5 s
Light of which of the following colors is scattered most in the atmosphere?
blue
The Swedish flag is blue and yellow. When viewed with blue light it appears
blue and black
the wavelength of this figure is
d
The bending of waves around the edge of an obstacle in their path is an example of
diffraction
Which of the following is not a property of an electromagnetic wave?
electric charge
The property of light waves that leads to the phenomenon of color is
frequency
When a sound wave goes from air into water, the quantity that remains unchanged is its
frequency
A wave of amplitude A interferes with another wave of identical amplitude (A), frequency, wavelength, and phase. The resulting wave
has an amplitude of 2A.
Relative to its object, a real image formed by a lens is always
larger
You are looking at the bottom of a lake 1.2 m deep from a boat. To you the lake seems to be
less than 1.2 m deep
Relative to the focal length of a wide-angle camera lens, the focal length of a telephoto lens is
longer
The greater the decibel (dB) level of a sound wave, the
louder it is
In a transverse wave, the individual particles of the medium move
perpendicular to the direction of travel.
The image the lens of the eye forms on the retina is
real and inverted.
Light of which of the following colors has the longest wavelength?
red
The setting sun appears red because its light is
scattered
Of the following kinds of waves, those that cannot be polarized are
sound waves
Dispersion is the term used to describe the
splitting of white light into its component colors in refraction
Sound waves of frequency 300 Hz have a speed relative to sound waves in the same medium of frequency 600 Hz that is
the same
An example of a wave that is partly longitudinal and partly transverse is a
water wave
