Waves Flashcards
What does wave transfer?
Energy
What do waves do not transfer?
Matter
What are the waves that require material medium?
Mechanical waves
What are the waves that don’t require medium?
Electromagnetic waves
How do electromagnetic waves propagate?
Using electric and magnetic fields
What waves travel perpendicular to the direction of propagation of waves?
Transverse waves
Which waves consist of crest and trough?
Transverse waves
What waves travel in the direction of propagation of waves?
Longitudinal waves
What waves consist of rarefactions and compressions?
Longitudinal waves
What is the formula for wave speed?
v = √TL/M
Is speed in a thick string greater or thin string?
Thin string
Theoretically speed of sound is?
281 m/s
Experimental value of speed of sound is?
332 m/s
What did Laplace corrected?
Temperature doesn’t remain constant during compressions and rarefactions.
Range of frequencies dolphin hear?
150-150,000
Range of frequencies bat hear?
1000-20,000
Range of frequencies cat hear?
60-70,000
Range of frequencies dog hear?
15-50,000
Speed of sound depends upon?
v = ôRT/m
Speed of sound with the wind?
Increases
Speed of sound against the wind?
Decreases
Resultant of simultaneous waves acting upon the same point is known as?
Principle of Superposition
What is interference?
Two waves traveling in the same direction with same speed
What does slightly different frequencies of waves produce?
Beats
Two in phase waves meet to form?
Constructive interference
Two out of phase waves meet to form?
Destructive interference
What are the sources called for having phase difference constant?
Coherent
For constructive interference the path difference between the waves must be?
Zero or integral multiple of wavelength
For destructive interference the path difference is?
Odd integral multiple of wavelength/2
The point of zero displacement on stationary waves?
Nodes
The point of max. Amplitude on stationary waves?
Antinodes
Points between two successive nodes are?
In phase with each other
The distance between two consecutive nodes?
Wavelength/2
Frequency of first mode of vibration?
f1 = (√TL/M)/2L
Frequency of second mode of vibration?
f2 = 2(v/2L)
What are overtones?
Harmonics, integral multiple of fundamental frequency
What is Doppler effect?
The apparent change in frequencies of sound waves due to relative motion of the source or listener
If the frequencies of waves increases the object is moving?
Towards you
If the frequencies is decreasing, the object is moving?
Away from you
What is blue shift?
A star is moving closer to the surface of earth
What is red shift?
A star is moving away from the earth
Formula for source moving towards the listener?
f’ = (v/v - a)f
Formula for source moving away from the listener?
f’ = (v/v+a)f
Formula for listener to move towards the stationary sound source?
f’ = (v+b/v)f
Formula for listener moving away from the stationary sound source?
f’ = (v/v+b)f
Mono atomic 1.67
Di atomic 1.40
Poly atomic 1.29
