X and Y are different wave motions. In air, X travels much faster than Y but
has a much shorter wavelength. Which types of wave motion could X and Y
be?
X
Y
1.
microwaves
red light
2.
radio
infra red
3.
red light
sound
4.
sound
ultraviolet
5.
ultraviolet
radio
Solution not yet available
Astronauts are in a spaceship orbiting the moon. They see an explosion on the
surface of the moon. Why can they not hear the explosion?
explosions do not occur in space
sound cannot travel through a vacuum
sound is reflected away from the spaceship
sound travels too quickly in space to affect the ear drum
the spaceship would be moving at a supersonic speed
Solution not yet available
A man stands between two cliffs as shown in the diagram and claps his hands
once.
Assuming that the velocity of sound is \(\text{330}\)
\(\text{m·s$^{-1}$}\), what will be the time interval between the
two loudest echoes?
\(\frac{2}{3} \text{ s}\)
\(\frac{1}{6} \text{ s}\)
\(\frac{5}{6} \text{ s}\)
\(\text{1}\) \(\text{s}\)
\(\frac{1}{3} \text{ s}\)
Solution not yet available
A dolphin emits an ultrasonic wave with frequency of 0,15 MHz. The speed of
the ultrasonic wave in water is \(\text{1 500}\)
\(\text{m·s$^{-1}$}\). What is the wavelength of this wave in
water?
\(\text{0,1}\) \(\text{mm}\)
\(\text{1}\) \(\text{cm}\)
\(\text{10}\) \(\text{cm}\)
\(\text{10}\) \(\text{m}\)
\(\text{100}\) \(\text{m}\)
Solution not yet available
The amplitude and frequency of a sound wave are both increased. How are the
loudness and pitch of the sound affected?
loudness
pitch
A
increased
raised
B
increased
unchanged
C
increased
lowered
D
decreased
raised
E
decreased
lowered
Solution not yet available
A jet fighter travels slower than the speed of sound. Its speed is said to
be:
Mach 1
supersonic
subsonic
hypersonic
infrasonic
Solution not yet available
A sound wave is different from a light wave in that a sound wave is:
produced by a vibrating object and a light wave is not.
not capable of travelling through a vacuum.
not capable of diffracting and a light wave is.
capable of existing with a variety of frequencies and a light
wave has a single frequency.
Solution not yet available
At the same temperature, sound waves have the fastest speed in:
rock
milk
oxygen
sand
Solution not yet available
Two sound waves are travelling through a container of nitrogen gas. The first
wave has a wavelength of 1,5 m, while the second wave has a
wavelength of \(\text{4,5}\) \(\text{m}\). The velocity of the second
wave must be:
\(\frac{1}{9}\) the velocity of the first wave.
\(\frac{1}{3}\) the velocity of the first wave.
the same as the velocity of the first wave.
three times larger than the velocity of the first wave.
nine times larger than the velocity of the first wave.
Solution not yet available
A lightning storm creates both lightning and thunder. You see the lightning
almost immediately since light travels at \(\text{3} \times
\text{10}^{\text{8}}\) \(\text{m·s$^{-1}$}\). After seeing the
lightning, you count \(\text{5}\) \(\text{s$^{-1}$}\) and then you hear
the thunder. Calculate the distance to the location of the storm.
Solution not yet available
A person is yelling from a second story window to another person standing at
the garden gate, \(\text{50}\) \(\text{m}\) away. If the speed of sound
is \(\text{344}\) \(\text{m·s$^{-1}$}\), how long does it take the
sound to reach the person standing at the gate?
Solution not yet available
Person 1 speaks to person 2. Explain how the sound is created by person 1 and
how it is possible for person 2 to hear the conversation.
Solution not yet available
Sound cannot travel in space. Discuss what other modes of communication
astronauts can use when they are outside the space shuttle?
Solution not yet available
An automatic focus camera uses an ultrasonic sound wave to focus on objects.
The camera sends out sound waves which are reflected off distant objects
and return to the camera. A sensor detects the time it takes for the
waves to return and then determines the distance an object is from the
camera. If a sound wave (speed \(= \text{344}\text{ m·s$^{-1}$}\))
returns to the camera \(\text{0,150}\) \(\text{s}\) after leaving the
camera, how far away is the object?
Solution not yet available
Calculate the frequency (in Hz) and wavelength of the annoying sound made by
a mosquito when it beats its wings at the average rate of 600 wing beats
per second. Assume the speed of the sound waves is \(\text{344}\)
\(\text{m·s$^{-1}$}\).
Solution not yet available
How does halving the frequency of a wave source affect the speed of the
waves?
Solution not yet available
Humans can detect frequencies as high as \(\text{20 000}\)
\(\text{Hz}\). Assuming the speed of sound in air is \(\text{344}\)
\(\text{m·s$^{-1}$}\), calculate the wavelength of the sound
corresponding to the upper range of audible hearing.
Solution not yet available
An elephant trumpets at \(\text{10}\) \(\text{Hz}\)10 Hz. Assuming the
speed of sound in air is \(\text{344}\) \(\text{m·s$^{-1}$}\),
calculate the wavelength of this infrasonic sound wave made by the
elephant.
Solution not yet available
A ship sends a signal out to determine the depth of the ocean. The signal
returns 2,5 seconds later. If sound travels at
\(\text{1 450}\) \(\text{m·s$^{-1}$}\) in sea water, how deep
is the ocean at that point?
Solution not yet available
A person shouts at a cliff and hears an echo from the cliff \(\text{1}\)
\(\text{s}\) later. If the speed of sound is \(\text{344}\)
\(\text{m·s$^{-1}$}\), how far away is the cliff?
Solution not yet available
Select a word from Column B that best fits the description in Column A:
Column A
Column B
1. waves in the air caused by
vibrations
A. longitudinal waves
2. waves that move in one direction,
but medium moves in another
B. frequency
3. waves and medium that move in the
same direction
C. period
4. the distance between consecutive
points of a wave which are in phase
D. amplitude
5. how often a single wavelength
goes by
E. sound waves
6. half the difference between high
points and low points of waves
F. standing waves
7. the distance a wave covers per
time interval
G. transverse waves
8. the time taken for one wavelength
to pass a point