What Are Waves?
A disturbance involving the transfer of energy from place to place
Wave
The height of a waves crest depends on its:
Amplitude
(a unit of distance, usually measured in meters)
When a wave hits a surface, any part of a wave that cannot pass through the surface bounces back, and is called:
Reflection
A repeated back-and-forth or up-and-down motion
Vibration
The highest point on a transverse wave is called a:
Crest
The material through which a wave travels (can be a solid, liquid, or a gas)
Medium
The distance between two corresponding parts of a wave:
Wavelength
(a unit of distance, usually measured in meters)
The bending of waves due to a change in speed:
Refraction
(light waves will refract when moving from air into water, slowing the speed and causing objects to appear bent)
The lowest point on a transverse wave is called a:
Trough
The type of wave that vibrates a medium perpendicular (90 degrees) to the direction in which the wave travels
Transverse wave
The type of wave that forms when a source of energy causes a medium to vibrate
Mechanical waves
The number of times a wave passes a given point in a certain amount of time:
Frequency
measured in Hertz (Hz) which are a number of waves per second
When waves bend around barriers or pass through openings:
Diffraction
(Water waves and also sound waves will diffract around corners. This is why you are able to hear things happening in other rooms. The sound wave diffracts around the doorframe and bends into the room that you are in.)
In longitudinal waves, the areas in which the medium is pressed closer together are called:
Compressions
In longitudinal waves, the areas in between the compressed areas are called:
Rarefactions
Name the three types of Mechanical Waves:
Transverse Waves, Longitudinal Waves, and Surface Waves
The speed of a wave can be calculated using these two formulas:
Speed = Distance / Time
Speed = Frequency x Wavelength
Interference in which two waves combine to form a wave with a larger amplitude than any individual wave:
Constructive interference
(when sending two water waves toward each other, they will combine at a given point to create a taller wave before passing through one another in the direction they were traveling in)
Interference in which two waves combine to form a wave with a smaller amplitude than either original wave had is called:
Destructive interference
(When the crest of a wave meets the trough of a wave, the waves cancel each other out, resulting in a wave with a smaller amplitude, until each wave passes through the other in the original direction they were traveling in)
These types of waves occur in between two mediums, and are combinations of longitudinal and transverse waves:
Surface waves
(waves that move along the surface of water are moving in between two mediums - the water and the air)
Sound waves travel by causing air particles to vibrate in this type of wave:
Longitudinal
The speed of a mechanical wave will remain the same unless one of the following 3 things changes:
- the medium
- temperature
- pressure
A wave that appears to stand in one place. In reality there are two waves causing interference as they pass through each other:
Standing wave
An increase in the amplitude of a vibration that occurs when external vibrations match an object's natural frequency:
Resonance
(All objects vibrate. A glass vibrates at a specific frequency. If we match that frequency, we can make the glass vibrate. If we increase the amplitude of the vibrations by using a loud speaker, the medium will shatter, breaking the glass because of resonance)
Calculate the speed of a wave with a frequency of 10,000 Hz and a wavelength of 0.001 meters:
10 m/s
v = fλ