waves Flashcards
What are waves?
waves transfer energy and information but they do not transfer matter. energy is transferred via oscillations that the wave is travelling through
What are longitudinal waves?
Oscillations occur parallel to direction of movement. surface pushes air molecules away. e.g. SOUND WAVES
What are transverse waves?
oscillations occur up and down at a 90° angle in directon of travel. they don’t move position they move up and down. e.g. LIGHT WAVES, ELECTROMAGNETIC WAVES
what is frequency?
the number of waves produced at a certain point per second. measured in Hz. 1Hz is 1 wave per second.
What is time period?
time needed for the production of a complete wave. measured in seconds
what is the relationship between f and T?
f = 1/T
T= 1/f
What are seismic waves?
the types of waves that occur during an earthquake.
what are the 2 types of seismic waves?
P (primary or push waves) - Longitudinal
S (secondary or shake waves) - transverse
Describe P Waves
travel through solids liquids and gases as they are LONGITUDINAL waves and they use all of their energy by travelling through these.
describe s waves
travel through solids only because they are TRANSVERSE waves
What is the wavefront?
the observed or imagined lines drawn on both longitudinal waves and transverse waves diagrams in order to present where the wavelength will be measured.
What is the sign for wavelength and what do we measure it in?
λ and metres
what is the sign for amplitude and what do we measure it in?
A and metres.
how do we work out the wavespeed?
speed = distance/time
wavespeed (v/s) = wavelength (λ)/time period(T)
wavespeed = frequency/wavelength
what is refraction?
waves change direction when it hits a different medium. this is because the wave travels at different speeds through different media.
what is the law of refraction?
incident angle = refracted angle
what is reflection?
wave moves beck into the medium that it came from
what is the law of reflection?
angle of incidence = angle of reflection
what is diffraction?
the wave bends a little as it passes through an opening. THE SMALLER THE GAP, THE MORE THE WAVE SPREADS OUT AND BENDS. the maximum bending occurs when the gap size is the same as the wavelength
describe the dispersion of light
the white light is made up of 7 different colours: red orange yellow green blue indigo violet
why does the white light split into colours?
because each colour travels at different speeds and the angles of refraction are all different
why is red at the top?
because red has the longest wavelength and smallest refraction. it has the most reflection
