P11: Waves 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 two 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 a 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 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 to calculate wave speed?
Wave speed = frequency x Wavelength
What wor is used to describe when a wave bounces off a surface?
Reflection
How do sound waves travel through a solid?
The particles in a solid vibrate and transfer kinetic energy through the material
What are ultrasound waves?
Waves which have a frequency higher than the upper limit of human hearing
What natural event causes seismic waves to be produced? What types are produced?
Esrthquakes
They produce both P-waves and S-waves
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 speed 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 do waves refract when entering a denser medium?
They band towards the normal
The angle of refraction is less than the angle of incidence
What type of eaves cna 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 orginate from?
They originate from changes in the nuclei of atoms
What health effects can ultraviolet waves cause?
They can cause skin to age prematurely
They can increase the risk of developing skin cancer
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 3 practical uses of infrred radiation?
Electrical heaters
Cooking food
Infrared cameras
Give 2 practical uses for microwave radiation?
Satellite communications
Cooking food
Give 2 practical uses for radio waves?
Television transmission
Radio transmission
