6.1 Waves in air, fluids and solids Flashcards
What are the two types of waves?
● Transverse
● Longitudinal
What is a transverse wave?
A wave for which the oscillations are perpendicular to the direction of the energy transfer
What is a longitudinal wave?
A wave for which the oscillations are parallel to the direction of energy transfer
Give three examples of transverse waves
● Electromagnetic waves
● Seismic S-waves
● Mexican wave
Give three examples of longitudinal waves
● Sound waves
● Seismic P-waves
● Ultrasound waves
What are the two parts of a longitudinal wave called?
Compressions and rarefactions
What is a wave’s amplitude?
The maximum displacement of a point on a wave from its undisturbed position
What is wavelength?
The distance from a point on a wave to the same position on the adjacent wave. Most commonly peak to peak or trough to trough.
What is the frequency of a wave?
The number of waves that pass a given point each second
What is the unit used for frequency?
Hertz (Hz)
What is meant by a frequency of 200Hz?
200 waves pass a given point each second
What is wave speed?
The speed at which the wave moves or at which energy is transferred through a medium
What does a wave transfer?
Energy
State the equation used to calculate wave speed. Give appropriate units.
Wave speed = Frequency x Wavelength
Speed (m/s), Frequency (Hz), Wavelength (m)
What word is used to describe when a wave bounces off a surface?
Reflection
How do sound waves travel through a solid? (Higher)
The particles in the solid vibrate and transfer kinetic energy through the material
What is the frequency range of human hearing? (Higher)
200Hz - 20kHz
1kHz = 1000Hz
What are ultrasound waves? (Higher)
Waves which have a frequency higher than the upper limit of human hearing (20kHz)
Give an example use for ultrasound waves
Medical or industrial imaging
What natural event causes seismic waves to be produced? (Higher)
Earthquakes
What are the two types of seismic waves? (Higher)
● Seismic P-waves
● Seismic S-waves
State a difference between the mediums that S-waves and P-waves can travel through. (Higher)
P-waves travel through both solids and liquids
S-waves only travel through solids (not liquids)
What technique is used to detect objects in deep water and measure water depth? (Higher)
Echo sounding - high frequency sound waves are emitted, reflected and then detected. Time difference between emission and detection, alongside wave speed, are used to calculate distances.
