Waves in air, fluids and solids Flashcards
What are the 2 types of waves?
- Transverse.
- Longitudinal.
What is a transverse wave?
A wave for which the oscillations are perpendicular to the direction of energy transfer.
What is a longitudinal wave?
A wave for which the oscillations are parallel to the direction of energy transfer.
Give 2 examples of transverse waves
- Electromagnetic waves.
- Seismic s-waves.
Give 2 examples of longitudinal waves
- Sound waves.
- Seismic p-waves.
What are the 2 parts of a longitudinal wave called?
Compressions and rarefractions.
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 boundary/surface?
Reflection.
How do sound waves travel through a solid?
The particles in the solid vibrate and transfer KE through the material.
What is the frequency range of human hearing?
20 Hz - 20kHz.
1kHz - 1000 Hz
What are ultrasound waves?
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 wave to be produced? What types are produced?
- Earthquakes.
- They produce both P-waves and S-waves.
State a difference between the mediums that P-waves and S-waves can travel through
- 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?
- Echo sounding.
- High frequency sound waves are emitted, reflected and detected.
- Time difference between emission are detected alongside wave speed, are used to calculated distances (equation for speed, distance, time).
What property of waves in different mediums cause refraction?
- Velocity.
- Wave speed is slower in denser materials, causing refraction.
In which direction do waves refract when entering a denser medium?
- When entering a more dense medium, the wave slows down.
- This causes the wave to bend towards the normal.
- This leads to the angle of refraction being less than the angle of incidence.
