This document discusses different types of waves including mechanical/elastic waves, electromagnetic waves, transverse waves, and longitudinal waves. Mechanical waves require a medium and include sound and water waves, while electromagnetic waves can propagate through a vacuum such as radio waves. Transverse waves involve particles vibrating perpendicular to the propagation direction, while longitudinal waves involve particles vibrating parallel. Other topics covered include wavelength, amplitude, frequency, wave velocity, interference, stationary waves, beats, and simple harmonic motion.
2. Wave motion is a form of disturbance which
travels forward (in material medium or
vacuum) due to repeated periodic motion of
particles about their mean position and
motion being transferred from one particle to
another in direction of propagation of wave.
3. Mechanical or Elastic Waves:
They compulsorily require material
medium for propagation. For e.g. Sound
Waves, Water Waves (Ripples), Waves in
Strings and Ropes
The medium in which mechanical waves
propagate must possess inertia and elasticity
(so that particle can come to its original
position & shape also can transfer its energy
to next particle)
4. Electromagnetic Waves
The waves which do not require material
medium for their propagation and can travel
in vacuum. For e.g. Radio Waves, Microwaves,
X rays.
Remember
Wave Motion is just the transfer of energy not
te transfer of matter.
5. Transverse Waves are those in which particles
of medium vibrate along the mean position in
direction at right angles to direction of
propagation of wave. E.g ripples, waves in
string
Transverse Waves
6. Transverse Waves are those in which particles
of medium vibrate back and forth along the
mean position along the direction of
propagation of wave. E.g Sound Waves, Waves
produced in spring
9. Features of Longitudinal Waves
Features of Transverse Waves
Difference between Longitudinal and
Transverse Waves
Sound Waves and their properties
Light Waves and their properties
Numerical to be practiced on formulae v = nλ
v= wave velocity, n= frequency, λ =
wavelength
10. Periodic Motion: A Motion which repeats itself
after certain interval of time. E.g. Pulse beat,
Pendulum of clock, Rotation of earth around its
axis.
Oscillatory Motion: Any back and forth motion
which equal intervals of time about fixed time.
E.g. Vibrations of strings on musical
instruments, oscillations of mass about spring.
Remember every oscillatory motion is periodic
but every periodic motion is not oscillatory
11. A body is said to execute SHM if its
acceleration is directly proportional to its
displacement from a fixed point (mean
position) and always directed to that point.
E.g. Motion of piston of engine, Vibrations of
prongs of tuning fork.
12. Harmonic Oscillator: A body which executes
SHM.
Displacement, y: The distance travelled by
vibrating particle from its mean position.
Amplitude, A: Maximum displacement of
particle from mean position.
Time period, T: Time taken by particle to
move from mean to one extreme position and
back to mean position.
13. Frequency, n: Number of Vibrations
completed by particle per second. Units
Hertz, per sec.
Angular velocity, ω: Rate of change of
angular displacement, ϴ. Units radians/sec
Phase: State of particle with respect to its
mean position (means how much angle it is
away from mean position)
Phase Difference: The difference is phases of
two particles oscillating at any instant of
time.
14.
15. A Progressive Wave is one which travels in a
given direction in a medium with same
amplitude and constant speed.
Equation y = a Sin ωt
y = a Sin 2πt/T {ω = 2π / T}
16. The redistribution of energy in medium when two
or more waves arrive at a point at same instant of
time.
Principle of Superposition of Waves: If two or
more waves are moving through medium then
resultant displacement at any point is algebraic
sum of the displacement
17. Two waves of same frequency moving in
same direction result in interference.
Two waves of same frequency moving in
opposite direction produce stationary waves.
Two waves of slightly different frequencies
moving in same direction give rise to beats.
19. Constructive Interference: The redistribution
of energy when two waves in same phase
superimpose upon each other.
Destructive Interference: The redistribution of
energy when two waves in opposite phase
superimpose upon each other.
20.
21. When two identical waves travel through a
medium along the same line in opposite
directions, they superimpose on each other
give rise to new types of waves which appear
to be stationary in space.
22. Topics to be done Characteristics of
Stationary Waves.
Comparison between Progressive and
Stationary Waves
23. The periodic rise and fall in the intensity or
loudness of sound caused by the
superposition of two sound waves of slightly
different frequencies.
24. Read and memorize the definitions with
examples of above mentioned types of
vibrations.
Mathematical part of SHM will be discussed.