2. Medium II. Pulses and Waves
medium – what a pulse or wave _________________________
__________ (The plural of medium is __________ .)
propagates (moves)
through
media
Medium
pulse
energy moves
_______________
the source by the
pulse or wave
energy
_____________
source
disturbs the
medium here
away from
wave
Pulses and waves are caused by ____________________
and transmit ____________ (but NOT ____________)
through the __________________ .
vibrations
energy
mass
medium

3. Examples of Waves (or Pulses) and their Media:
– require a medium: _______________________
because the wave ____________________________
of the medium as it passes through it
- ___________ propagate in a vacuum
Sound
solids, liquids or gases
displaces the particles
cannot
____________ waves:
– ________________________ a medium
- are composed of _______________________ fields
- can propagate ___________________ as well as
in solids, liquids and gases.
Light
do NOT require
electromagnetic
in a vacuum

4. single disturbance
pulse - a __________________________ that propagates
through a medium
velocity
v = ______________ of pulse A
equilibrium
___________ position of'
the particles in medium
the maximum displacement
amplitude A - _______________________________of the
medium as the pulse or wave passes
through it

5. wave - a ___________________________disturbance that
periodic (regular)
wave - a ___________________________disturbance that
propagates through a medium
crest (peak) v A A
________________
position of medium
equilibrium
trough
Only ___________________ is usually shown. Unless
otherwise stated, it is usually assumed that the wave
___________________________________________________
The diagram shows a __________________ at one time.
part of the wave
continues infinitely in both directions
snapshot

6. A. The amplitude A of a wave determines how much
_____________ it transmits. The energy transported
is proportional to the ___________________ .
energy
square of A
Amplitude: _______ _______ ________
Energy: _______ _______ ________ A 2A 4A 4E
16E E
loudness
Sound: Amplitude determines ______________
small A: ________   large A: _________
Light: Amplitude determines ________________
small A: ________   large A: _________
soft
loud
brightness
dim
bright

7. Ex: Radio waves and light are types of ___________________
radiation. One way that information can be sent by
radio waves is by _____________________ (changing) the
wave's ___________________ : This is called _____. Here
is how it is done:
electromagnetic
modulating
amplitude AM
1. This wave has the
___________________
info to be sent
2. This wave is called
the ____________
carrier
AM wave
3. This is the ___________
The ____________ wave's
amplitude has been
______________ by wave 1.
carrier
modulated

8. B. The 3 basic types of waves:
The medium v is ___ the wave v
Ex: ____________________________
transverse
medium v ┴
wave v
light, S earthquake waves
Displacement d
_________________ of the medium as the wave moves
to the right:
_______ v
wave
neg. d x
equilibrium
pos. d
Where is the displacement zero?

9. 2. _________________ waves
The medium v is ___ the wave v
Ex: ___________________________
longitudinal ||
medium v
sound, P earthquake waves
wave v
Displacement d
_________________ of the medium as the wave moves
to the right:
_______ v
wave
pos. d
neg. d
Where is the displacement zero?

10. ________________ waves:
The medium v is __________________ to the wave v.
Ex: ____________________________________
Combination
both ┴ and||
water, some earthquake waves
medium v
wave v
Because it is easier to visualize, both
___________________ and ____________________waves
are drawn as if they were _________________ waves.
longitudinal
combination
transverse

12. ┴ A transverse pulse moving to the right: at rest
particle ____________
at rest
moving ____ up
later
max.
_________displacement
later
down
moving __________
later
at rest
____________
later ┴
Note: particle of medium moves _____ to wave v

13. A transverse wave moving to the right:
In which direction is the medium moving at points… 1 5 4 2 6 3
Imagine the wave at a slightly later time.
Note: Top points 1 and 5 are moving __________
Bottom point 3 is moving _________
Points 2 and 6 are moving ___________
Point 4 is moving ____________.
down up up
down

14. A transverse wave moving to the left:
In which direction is the medium moving at points… 1 5 4 2 6 3
Imagine the wave at a slightly later time.
Note: Top points 1 and 5 are moving ___________.
Bottom point 3 is moving __________
Points 2 and 6 are moving _________
Point 4 is moving __________.
down up
down up

15. l C. _______________ l (__________): the ______________
between two __________________ points on a wave
that have the same:
1. _____________________________ , and
2. __________________________ .
distance
Wavelength
lambda
consecutive
distance from equilibrium
direction of motion v
= ____ l x z d
= ____ y
_____________  same ______________ from equilibrium.
Only __________  moving in the same ________________.
x, y, z
distance
x and z
direction

16. In sum, l is the distance between consecutive _________________on a wave.
similar points l
l/4 l l l
l/2
l/4
l/2

17. Wavelengths are sometimes measured in terms of
________________ . In this case:
____ l = _________
angles 1
3600
2700
1800
900
These angles are sometimes called the ______________
or ____________________ of the wave.
phase
phase angle

18. Two points on a wave that are 1l (3600) apart or
a multiple of 1l are said to be ____________________
in phase
Two points on a wave that are (½)l (1800) apart or
a multiple of (1/2)l are said to be __________________
________________________ .
completely
out of phase
Label points on the wave below that are in phase with
point A. Then label the points that are completely
out of phase with A. Repeat for point B.
= in phase
= out of phase B A