Waves Flashcards
What is a wave?
It is the propagation of a disturbance created in a medium away from its source
What is the purpose of a wave?
To transfer energy
What are the 2 types of waves?
Transverse waves and Longitudinal waves
What is a transverse wave?
It is a wave in which the molecules vibrate perpendicular to the direction of the wave
What is a longitudinal wave?
It is a wave in which the molecules vibrate parallel to the direction of the wave
What are the differences between a transverse and a longitudinal wave?
A longitudinal wave consists of alternate regions of compression and rarefaction and the particles vibrate parallel to the direction of the wave, while a transverse wave consists of alternate crests and troughs and the particles vibrate perpendicular to the direction of the wave
What is amplitude?
The maximum displacement of the molecules from the undisturbed surface
What is displacement?
It is the distance moved by the particles of a medium from the undisturbed surface
What is the time period?
It is the time taken to complete one wave
What is frequency and the formula and unit?
It is the number of waves completed in 1 second. F = 1/T. Hz
What is wavelength?
It is the horizontal distance between 2 consecutive crests/troughs
Formula to measure the speed of a wave
V = F(lamda)
What is the wavefront?
It is a line along which all particles are at their maximum displacement
What are the different type of wavefronts?
Parallel and Circular
What is the distance between two consecutive wavefronts?
The wavelength
Purpose of a vibrator in a ripple tank?
Used to produce disturbance in water
Purpose of the white screen in a ripple tank setup
To observe the image of the wave pattern
Purpose of elastic band in a ripple tank
It controls the up and down movement of the vibrator
How do you produce parallel wavefronts in a ripple tank?
A sharp metal strip is connected below the vibrator. When the vibrator is switched on, parallel wavefronts are seen on the white screen and they keep shifting away from the vibrator
How do you produce circular wavefronts in a ripple tank?
A metal sphere is connected below the vibrator. When the vibrator is switched on, circular wavefronts are seen on the white screen and they move away from the vibrator
How do you demonstrate reflection of parallel waves in a ripple tank?
A metal barrier is placed a short distance from the vibrator in an inclined position. When the vibrator moves up and down, wavefronts are seen to move towards the barrier and also away from the barrier in another direction. This shows reflection has taken place
How you do demonstrate refraction of parallel wavefronts in a ripple tank? (4)
1) Two regions (deep and shallow) are created by placing a plastic sheet a short distance away from the vibrator.
2) When the vibrator is switched on, parallel wavefronts of constant wavelength will be produced.
3) When the wavefronts travel in the shallower region, the wavefronts are seen to be closer.
4) This means that velocity has decreased and therefore refraction has taken place.
How do you convert KHz to Hz?
1KHz —-> 1000KHz
Multiply by 1000
