Waves (Basic) Flashcards
What is a wave?
A wave is an oscillation in a medium.
Waves can transfer energy and information.
What is an ‘oscillation’?
An oscillation is another word for a vibration.
When discussing waves, what is meant by the word ‘medium’?
A ‘medium’ is the material through which a wave passes.
What is the medium for surface waves in the ocean?
Water is the medium.
What is the medium for sound waves in this room?
Air is the medium.
What is the medium for waves on a slinky?
The slinky is the medium.
Give the definition of ‘wave direction’
‘Wave direction’ is the direction in which the wave transfers energy.
Give the definition of ‘a transverse wave’
A transverse wave is a wave where the medium oscillates perpendicular to the direction of energy transfer.
Give the definition of ‘a longitudinal wave’
A longitudinal wave is a wave where the medium oscillates parallel to the direction of energy transfer.
Give three examples of transverse waves
Waves on the surface of the ocean
Light waves
Infra-red waves
(also: all electromagnetic waves are transferse, e.g. radio, microwave, UV)
Give three examples of longitudinal waves
P-waves from an earthquake
Sound waves
Ultrasound waves
What is meant by the ‘wavelength’ of a wave?
The wavelength is the distance between two neighbouring peaks (or two troughs) on a wave.
What are the units of wavelength?
Wavelength is a length, and like all lengths it is measured in metres. (m)
What is meant by the ‘period’ or ‘time period’ of a wave?
The time period of a wave is the time for one complete oscillation to occur.
What are the units of ‘period’?
The ‘period’ or ‘time period’ of a wave is a time, and like all times it is measured in seconds. (s)
What is meant by the frequency of a wave?
The number of complete oscillations that pass a point, per second.
What are the units of frequency?
The units of frequency are Hertz. (Hz)
Define the ‘amplitude’ of a wave.
The amplitude is the maximum displacement caused by a wave.
OR The amplitude is the displacement from the line of zero displacement to the peak of a wave.
What are the units of amplitude?
Amplitude is a distance, so the units of amplitude are metres. (m)
You hear two sound waves. The second wave has the same frequency as the first, but a bigger amplitude. How does it sound different?
It sounds louder.
You have to say ‘louder’ at GCSE. ‘Loud’ would be marked wrong.
You hear two sound waves. The second wave has the same amplitude as the first, but a bigger frequency. How does it sound different?
It sounds higher pitched.
You have to say ‘higher’ at GCSE. ‘High’ would be marked wrong.
You see two light waves. The second wave has the same amplitude as the first, but a bigger frequency. How does it look different?
It is a different colour.
It would be closer to the blue end of the spectrum that the first light wave
You see two light waves. The second wave has the same frequency as the first, but a bigger amplitude. How does it look different?
It looks brighter.
You have to say ‘brighter’ at GCSE. ‘Bright’ would be marked wrong.