P6 Waves Flashcards
Describe a Longitudinal wave.
Longitudinal waves oscillate in parallel to the direction of energy transfer. E.G. sound waves, seismic P waves
Describe a transverse wave.
Transverse waves oscillate in perpendicular to the direction of energy. E.g. water waves, Seismic S waves.
What is the wavelength of a wave?
The length of one complete wave.
What is the time period of a wave?
time taken for one wave to pass. (s)
What is the frequency of a wave?
number of waves that pass every second (Hz).
What is the relationship between frequency and time period.
They are reciprocals.
what is the equation for wave speed?
Wavespeed = frequency x wavelength.
What happens with sound waves?
Makes the eardrum vibrate.
What frequencies can humans hear?
20Hz to 20,000Hz.
What state can transverse s waves not pass through?
Liquid.
What happens when a wave reflects off a smooth surface?
Angle of incidence = angle of reflection
What happens when waves reflect off of a rough surface?
Light will be scattered.
What waves can travel through space?
Electromagnetic waves.
What waves make up the EM spectrum?
Radio waves, Microwaves, Infra-red, visible light, UV, X-rays and Gamma rays
How are EM waves emitted and absorbed?
By electrons apart from Gamma which is through nuclei.
What is ionising radiation?
When wave energy is high enough it can cause electrons to leave its atom, this leaves an ions. UV, X-rays and Gamma rays are all examples of ionising radiation.
What does a convex lens do?
Makes rays converge.
What is the equation for magnification?
Magnification = image height / object height
Why do objects appear different colours?
Reflects those coloured wavelengths and absorbs others.
