3. VIBRATIONS OF A PENDULUM
Vibration
Wiggles in TIME
Swings forth and back
By its nature, it wiggles
Galileo Galilei
Pisa Cathedral; chandelier
Isochronism of the pendulum
Length and Mass
Length affects the number of swings
Mass does not affect the number of swings
4. “The crests
and
PARTS OF A WAVE troughs of
the sea of
life that
flows”
6. PARTS OF A WAVE
Crest
Highest point away from the equilibrium
Trough
Lowest point away from the equilibrium
Amplitude [ A ]
Size of the maximum disturbance away from the equilibrium
Distance from the equilibrium to the crest or trough
Wavelength [ λ ]
One cycle from the equilibrium
Distance between one full crest to one full trough
Minimum distance for a wave to repeat itself
Distance between two successive, identical parts of the wave
9. ENERGY TRANSFER
Mass and energy are
transferred
Energy is transferred but
not mass
A continuous production of
pulses creates a wave
10. CHARACTERISTICS OF WAVES
1. A wave transfers energy
2. A wave does not transfer matter from one place to another
3. A wave transmits information
1.5
1
0.5
0
210
75
90
315
0
15
30
45
60
105
120
150
195
225
255
285
300
330
345
360
165
240
270
180
135
-0.5
-1
-1.5
11. T YPES OF WAVES
Mechanical Wave
Waves that need a medium
to travel
Electromagnetic Waves
Waves that do not need a
medium to travel
Medium
Material used for energy to
travel
Can be solid liquid or gas
12. T YPES OF WAVES
Longitudinal Waves
a wave who’s direction
of propagation is
parallel to the direction
of vibration
Transverse Waves
a wave who’s direction
of propagation is
perpendicular to the
direction of vibration
A longitudinal wave
can be represented as
a transverse wave and
vice versa
17. DEFINITIONS
Wave Motion
Transfer of energy from the source to a distant receiver without the
transfer of matter.
Precise Definition for Wavelength
A wavelength is the distance between two successive particles
vibrating in phase
Phase of the Wave
The motion, direction and position of a particle within the wave
sequence
18. PHASE
In Phase
Particles have the same displacement and are moving in the same
direction
Particles that are an integral number of wavelengths apart are
vibrating in phase
Out of Phase
Particles that have opposite displacement and are moving in
opposite directions
Particles in one wavelength have the same frequency and
amplitude but there is a phase lead from one particle to the
next
Particles that are a half of a wavelength or a half plus an
integral amount of wavelengths are exactly or totally out of
phase