```Waves in Physics
Waves
Review
Multiple
Choice
Multiple Choice
Written
Response
Written Response
Waves
There are several types of waves. Perhaps the first types of waves, which may
come to mind, are ocean waves. Waves are defined as disturbances which carry
energy but do not carry matter. On a much smaller scale than an ocean wave,
you have probably seen a stone thrown into a pond. The energy from the initial
impact of the stone on the water creates waves which can be seen traveling
outward from the center. As the energy moves outward, the molecules of water
collide with each other like a chain reaction. Waves like this, which require
matter in order to transfer energy, are called mechanical waves.
As a Transverse Wave travels through a medium, the matter moves at a right
angle to the direction in which the wave is traveling. One example of a
mechanical transverse wave is when a person cracks a whip. When a lion
trainer cracks a whip, it may look as if the whip is moving away from his/her
hand, but in actuality, it was only the energy carried by the wave. Another
example of a mechanical transverse wave is if you were to anchor one side of a
rope to a door knob and begin to shake the other side. The energy from shaking
the rope causes the rope to move toward a perpendicular point from the direction
that the energy is moving.
Compressional waves are also mechanical, but the medium travels in the same
direction as the energy. An example of mechanical compressional waves is a
spring or a coil. Notice that compressional waves move forward and backward,
but not perpendicular. Another example of mechanical compressional waves is
sound waves. Although you cannot see the medium in the air, which sound
waves use to travel, they are there. Remember from our study of the
atmosphere, the air which surrounds you contains molecules of Nitrogen,
Oxygen, Carbon Dioxide and many more. The vibration of these molecules and
subsequent waves, allow you to hear noises.
Seismic waves are generated by earthquakes. Interestingly, seismic waves
demonstrate characteristics of both transverse and compressional waves.
During an earthquake there are three types of waves produced at exactly the
same time. Primary waves, also known as P-waves, move back and forth like a
compression wave. The rocks actually compress and then expand. Secondary
waves travel perpendicular to the direction of the wave. Secondary waves, also
called S-waves, are an example of a transverse wave.
The final and most
destructive type of seismic wave is the surface wave. Surface waves move
rocks in a backward, rolling motion and in a side to side swaying motion.
Because buildings are made from solid materials, surface waves cause many
building’s foundations to crack and collapse.
There are waves which do not require a medium to travel through.
Electromagnetic waves can travel through space without the aid of a medium.
There are several different types of electromagnetic waves including; radio
waves, infrared waves, visible light waves, ultraviolet waves, x-rays, gamma
rays and microwaves. The differences between the various types of
electromagnetic waves are due to their properties.
There are three properties of waves, which you must be familiar with. The
amplitude of a wave is the distance from the resting point to the crest or trough
of a wave. The more energy a wave carries, the larger the amplitude of a wave
will be. The wavelength of a wave is the distance measured between two crests
or two troughs. Wavelength is the major characteristic which determines the
identification of electromagnetic waves. Radio waves, a form of electromagnetic
waves, have very large wavelengths, while gamma rays possess much smaller
wavelengths. The frequency of a wave is the number of wave lengths which
pass by a certain point in one second. The frequency of a wave is dependent
upon how fast the vibration which is producing the wave. Faster vibration results
in a higher frequency.
1. A wave can best be described as
o
o
o
o
A disturbances which carry energy but do not carry matter
B disturbances which carry matter but not energy
C a movement of atoms
D a movement of energy
2. Which of the following types of waves have the highest frequency?
o
o
o
o
A Micro Waves
B Gamma Waves
D Ultra Violet Waves
3. The type of wave which travels through a medium, whereby the matter
moves at a right angle to the direction in which the wave is traveling is
known as
o
o
o
o
A transverse wave
B compression wave
C sound wave
D seismic wave
4. The distance between two crests of a wave is known as
o
o
o
o
A trough
B wavelength
C wave height
D wave magnitude
Electromagnetic waves can travel through space without the aid of any
medium. Describe what happens if the frequencies of electromagnetic