11: Waves Flashcards
Define amplitude
Amplitude is the maximum displacement about equilibrium position
Define period
Period is the time taken for one revolution
Define frequency
Frequency is the number of oscillations per unit time
Define wave speed
Wave speed is the distance traveled by the wave per unit time
Define wavefront
Wavefront is the imaginary line joining all points of the waves that are in phase
Define Transverse Waves
Transverse waves refers to waves where oscillations of the particles is perpendicular to direction of wave propagation/energy transfer
Define Longitudinal wave
Longitudinal waves are waves where the oscillation of particles is parallel to the direction of wave propagation/energy transfer
Difference between displacement-time vs displacement-distance graph
displacement-time shows period
displacement-distance shows wavelength
Proof v = f x wavelength
speed = distance/time
v = wavelength x (1/t)
v = f x lamda (shown)
How to calculate phase difference between two waves?
- Find difference in wavelength/time between two points of same amplitude
- phase diff = difference/one wavelength or on period
Define wave intensity
Wave intensity is the rate of change of transfer of energy per unit area perpendicular to direction of wave
Equation for energy of wave
energy = 1/2 x mass of particle x angular velocity^2 x Amplitude^2
What is wave intensity proportional to?
I is proportional to amplitude^2
I is proportional to 1/Area
Define polarisation
Polarisation is a process whereby the oscillation of the particle in a transverse wave is restricted to a single direction, in the plane normal to the direction of energy transfer
Why can’t sound waves be polarised?
Sound waves are longitudinal waves, thus oscillation of particles is in the direction parallel to wave propagation
Thus oscillation cannot be restricted to plane normal to the direction of wave propagation
