Waves Flashcards
Define waves
A wave is a periodic disturbance travelling through space, characterised by a vibrating medium.
What is a progressive wave?
Waves that carries energy from one place to another through a material or a vaccum are called progressive waves.
What are the two properties in which the movement of progressive waves is dependent upon?
Direction of propagation of energy (Wave).
Direction of Oscillation of particles of medium.
Define longitudinal waves.
If particles of medium oscillate parallel to to direction of propagation of energy the wave is longitudinal.
Define transverse waves.
If particles of medium oscillate perpendicular to the direction of propagation of energy the wave is transverse.
Define oscillation.
Repeated back and forth movements on either side of any equilibrium position.
An oscillation is a more specific term for vibration.
What is formed in longitudinal waves?
In longitudinal waves compressions and rarefractions are produced.
What are rarefractions?
Particles are further apart than their normal spacing. These regions have lower density and lower pressure than their normal values.
What are compressions?
Particles of medium are closer than their normal spacing. These regions have higher density than normal and pressure is at maximum.
What is formed in transverse waves?
Crests(top) and Troughs(bottom)
Define displacement:
The distance of a point on the wave from its undisturbed position or equilibrium position. Represented by x. Measured in m-meters.
Define amplitude:
The maximum displacement of a wave from the equilibrium position represented by A. Measured in m-metres. The greater the amplitude of the wave, the louder the sound.
Define wavelength:
Distance travelled while the particle of the medium completed on oscillation is called wavelength. Measured in metres and is represented by λ. note; when particle completes one oscillation wave travels exactly one wavelength.
What is the formula for speed of wave?
Speed of wave=Wavelength/Time Period
V= λ/T
But we know 1/T=F
So V= λ x 1/t
V=f λ
v=ms-1 v=m T=s
Define time period
Time period=Time taken for any wave to travel exactly one wavelength is called time period.
Time period=Total Time Taken/Number
Number can be of waves, crests, troughs, compression,rarefraction, oscillations, laps etc.