Unit 6 - Waves 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 energy
transfer.
What is a longitudinal wave?
A wave for which the oscillations are
parallel to the direction of energy
transfer
Give two examples of transverse waves.
- Electromagnetic waves
- Seismic s-waves
Give two examples of longitudinal
waves.
- Sound waves
- Seismic p-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?
The particles in the solid vibrate and
transfer kinetic energy 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).
What natural event causes seismic
waves 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 and detection,
alongside wave speed, are used to calculate
distances
What type of spectrum do
electromagnetic waves form?
A continuous spectrum.
Order the types of electromagnetic
radiation from lowest to highest
frequency.
● Radio waves
● Microwaves
● Infrared
● Visible Light
● Ultraviolet
● X-rays
● Gamma Rays
How do the speeds of EM radiation differ
in a vacuum and in air?
Electromagnetic waves all travel at the
same speed in a vacuum and in air.
What property of waves in different
mediums causes refraction?
● Velocity
● Wave speed is slower in denser
materials, causing refraction
In which direction (relative to the normal)
do waves refract when entering a denser
medium?
● They bend towards the normal
● The angle of refraction is less than the
angle of incidence
What type of waves can be produced by
oscillations in an electrical circuit?
Radio waves.
How can radio waves create an
alternating current in a circuit?
When radio waves are absorbed, they
can induce oscillations in a circuit with
the same frequency as the waves
themselves.
Where do gamma rays originate from?
They originate from changes in the
nuclei of atoms.
What health effects can ultraviolet waves
cause?
● They can cause the skin to age
prematurely
● The can increase the risk of
developing skin cancer
Give three practical uses for infrared
radiation
- Electrical heaters
- Cooking food
- Infrared cameras
What health effects can X-rays and
Gamma rays cause?
● They are ionising radiation so can
cause mutations in genes
● They can lead to increased risk of
developing various cancers
Give two practical uses for microwave
radiation.
- Satellite communications
- Cooking food
Give two practical uses for radio waves.
- Television transmission
- Radio transmission
