waves Flashcards
what is the relationship between the direction of energy transfer and vibration in a transverse wave ( wiggle) eg
the direction of vibration is perpendicular to the direction of energy transfer eg all waves in the electromagnetic spectrum, light waves and water waves
what is the relationship between the direction of vibration and wave travel in a longitudinal wave (barcode)eg
direction of vibration is parallel to the direction of wave travel eg sound waves
what is amplitude ?
amplitude is the vertical distance from the centre line to the top of a crest or the bottom of a trough (meters)
what is wavelength?
Wavelength is the horizontal distance between the point on one crest and the identical point on the next wave often this is done as one crest to the next or one trough to the next
what is frequency ?
frequency is the number of complete waves produced in 1 second or the number of waves passing a point in 1 second (Hz)
what is period?
period is the time taken for one complete wave to be produced. (seconds)
what does f=N/t mean?
frequency= number of waves ÷ time in seconds
what does f=1/T mean
frequency = 1 ÷ period
what does T=1÷ f mean
period = 1 ÷ frequency
what is diffraction?
diffraction is the bending of waves around obstacles example - water waves passing through the gap Inna barrier
what is the order of the electro magnetic spectrum in order of increasing frequency and decreasing wavelength
radio + TV, microwaves, infrared, visible light, ultra violet, x - rays, gamma rays
which waves are the most dangerous
high frequency waves have high energy so x rays and gamma rays are the most dangerous
what are the common properties of em spectrum waves
- they are all transverse waves
- they all travel at the speed of light (3x108)
- they all travel through a vacuum
- they all travel in straight lines
what are the uses and detectors of radio + TV waves?
*used in telecommunications/ radio + TV/ broadcasting / RADAR
* detected by antennas or aerials
*Sources include stars, lightning, pulsars
what are uses, detectors and sources for microwaves?
- used in microwave ovens and telecommunications
- detected by antenna and aerivals
- Sources include stars, cosmic microwave background radiation