Chapter 16 Waves And Sound Flashcards
Particle motion occurs perpendicular to the direction of the disturbance of the wave
Transverse
What are the two common features to all waves
- A wave is a traveling disturbance
2. Wave carries energy from place to place
Particle motion occurs parallel to the line of travel of the disturbance of the wave
Longitudinal wave
Need a material medium through which they can travel as they transfer energy
Mechanical wave
Material through which the energy of mechanical wave is transferred from one particle to another
Medium
Need no medium through which travel
Electromagnetic waves
Single disturbance traveling through medium
Pulse
Consists of cycles or patterns that are produced over and over again at the same frequency
Periodic waves
What waves are consisted of
Cycles
Maximum excursion particle of the medium from the particles undisturbed position the distance between a crest or trough to the undisturbed position
Amplitude
The horizontal length between the two same points on consecutive cycles
Wavelength
Time it takes to make a cycle
Period
Number of cycles per second
Frequency
What characterizes the energy content of the mechanical waves
It’s amplitude
What occurs with the speed when the wave in the same medium
The speed is constant
What does the speed depend on
Properties of a new medium
What is the relationship between frequency and wavelength
Inversely related
What does not amplitude effect
Speed wavelength and frequency
What occurs when a wave reaches the boundary of the medium
Part of it is reflected
What happens to the remainder of a reflected wave
It is transmitted into the new medium
What remains the same whenever wave enters a new medium
The frequency
What is the speed of a wave determined by in a rope or similar material
The tension in the rope and the linear density of the rope
When two or more waves are present simultaneously at the same place
Interference
What does interference result in
The resultant disturbance is the sum of the disturbances of the individual waves
When two waves meet perfectly and the amplitudes are combined
Constructive interference
When two waves meet oppositely and he amplitude is negated
Destructive interference
Wave changing direction after encountering a barrier and the wave energy remains in original medium
Reflection
What is the law of reflection
The angle of reflection is equal to the angle of incidence measured relative to the normal line
Change in direction of waves at the boundary between two different media the wave enters new medium
Refraction
The bending of a wave around obstacles placed in its path
Diffraction
What does the reflected wave look like if the encountered barrier is rigid compared to the original medium
Wave will be inverted
What does the wave look like if the encountered barrier is flexible compared to the original medium
Wave will be upright
What happens to the reflection of a wave if the encountered barrier material is similar to the original medium
Very little wave energy is reflected most of it will transmit through the new medium in form of upright wave
Happens to the wave energy if the encountered barrier material is very different from the original medium
Most of the wave energy will reflect in the form of an inverted wave while very little will be transmitted into the new medium
What causes refraction
The change in the speed of a wave when it enters a new medium
What happens to the wave frequency refraction occurs
Remains the same
Where does the wave bend if it slows down whenever it enters the new medium
It bends towards the normal line
Where does the wave bend when it speeds up in a new medium
Bends away from the normal line
What does the extent of diffraction depend upon
The wavelength of the waves and the size of the obstacle
What is the proportion regarding diffraction
Diffraction amount is proportional to the wavelength over the size of the obstacle
What remains constant during diffraction
Wave speed and wave frequency
How is a standing wave formed
Formed by interfering waves traveling in the opposite direction these reflected waves have the same wavelength amplitude and speed
Stationary points on the rope the displacements of the interfering waves are equal and opposite
Node
What occurs in order to form a node
Destructive interference
The points of maximum amplitude where constructive interference is greatest
Antinodes
What is occurring in order to form an antinode
Constructive interference
What is the frequency relationship between the waves that form a standing wave
Interference of equal frequency waves
How many nodes and antinodes are in one cycle of a standing wave
Three nodes and two antinodes
Three antinodes and two nodes
What is the Doppler effect
The discrepancy between actual wave frequency and observed wave frequency that occurs due to the motion of the source with respect to the observer
What is true about the frequency when the source is moving towards the observer
The observed frequency is higher than the actual frequency of the source
What is true about the frequency if the source is moving away from the observer
The observed frequency is lower than the actual frequency of the source
What happens to the waves as the source moves
They bunch up in front of the source and spread out behind the source
When does the observed frequency match the source frequency
When the source is not moving toward or away from the observer
What is true about frequency if the source is moving at a constant velocity or speed
Frequencies constant
Happens to the frequency if the source is accelerating
Frequencies changing
Transverse wave
Wave motion is perpendicular to particle motion
Longitudinal wave
Wave motion is parallel to particle motion
If a pulse is sent along a rope, how does the rope behave at any given point after the pulse has passed
It returns to it’s original position, as if it were never disturbed
Waves are sent along a spring of fixed length. How can the speed of the waves in the spring be changed
It can’t be changed because wave speed is constant in medium
Does the frequency of the wave actually change during the Doppler effect
No the observer just perceives it to change due to the relative motion of the source
What does the degree to which the observed frequency differs from the source frequency depend upon
Velocity of the wave, observer and source
What does the principle of linear superposition state
When waves interfere the resulting disturbance is the sum of the individual wave disturbances
