Waves and electromagnetic spectrum Flashcards
(19 cards)
What is the equation for Wave speed?
wave speed = frequency x wavelength
What is wave speed measured in?
meters per second-m/s
What is frequency measured in?
Hertz-Hz
What is wavelength measured in?
Meters-m
What is refraction?
Refraction is the change in direction of a wave at such a boundary.
What type of wave is a sound wave?
Longitudinal wave
Explain sound waves
They cause particles to vibrate parallel to the direction of wave travel. The vibrations can travel through solids, liquids or gases. The speed of sound depends on the medium through which it is travelling. When travelling through air, the speed of sound is about 330 metres per second (m/s). Sound cannot travel through a vacuum because there are no particles to carry the vibrations.
What frequency is ultra sound have to be above
20,000 Hz
What is ultrasound used for?
It is used in medicine, including ultrasound scans to check on the health of unborn babies, can be used to clean jewellery, can also be used for physiotherapy
What is infrasound?
It is any sound under 20Hz (below human hearing)
What uses do infrasound have?
It is used to investigate the internal structure of our planet
What type of wave is a P-wave
Its a longitudinal wave
What type of wave is a S-wave
Its a transverse wave
What is the relative speed of a P-wave
Faster
What is the relative speed of a S-wave
slower
What can P-waves travel through
Solids and liquids
What can S-waves travel though
solids only
What do all bodies emit
radiation (As a body gets hotter, it emits more high frequency electromagnetic radiation than low frequency. The higher the frequency, the shorter the wavelength. This means that the intensity of the radiation emitted is greater for a hotter body)
What are black bodies?
Are objects that are almost perfect at absorbing or emitting wavelength
