Waves Pre-Assessment
Characteristics of Waves
1 and 2. Draw & label a sine
curve.
D
i
s
p
l
a
c
e
m
e
n
t
a
m
p
l
i
t
u
d
e
Crests
Wavelength
Trough
3.
•The highest
points on a
transverse wave
are called
crests.
4.
•The lowest
points on a
transverse wave
are called the
troughs.
5.
• The greatest distance
that particles are
displaced from their
normal resting
positions because of a
wave is called the
amplitude.
6. Define compression
• Compression is crowded
coiled areas on a spring.
Area of compression
7. Define rarefaction
• Stretched out areas on a spring.
Area of rarefaction
8.
• The distance from
one crest of a
wave to the crest
of the next wave is
called the
wavelength.
9.
• The time required for
one full wavelength
of a wave to pass a
certain point is called
the period.
10.
• The frequency of a
wave is the number of
full wavelengths that
pass a point in a given
time interval.
11. Write the frequency-period
equation.
• Frequency (f) =
1/period or 1/T
• Frequency is
measured in Hertz and
period is measured in
seconds.
12. The full range of light at
different frequencies is called
the
•EM spectrum .
13. Frequency is measured in
the unit of
•HERTZ (Hz)
•Or Cycles/second
14. Wavelength is measured in
the unit of
• LENGTH (meter)
• It could also be in
nm, cm, or mm.
15. Speed =
• Wavelength (l) /
period (T)
• The Greek letter
lamda (l) is the
symbol for
wavelength
16. Speed =
•Frequency (f) /
wavelength (l)
•Or f / l
17. The symbol for frequency is
•f
•What unit is used to
measure frequency?
•Hertz (Hz)
18. The symbol for wavelength is
l
•Typically
wavelength is
measured in
nanometers (nm)
19. Write the wave-speed equation.
• V=fxl
• V = velocity or speed
• f=?
• Frequency
 l= ?
• wavelength
20. Sound travels better and
faster in
•water
21.
• Sound waves travel
faster in solids than in
air or water. (air and
water can be in either
order)
22.
•The speed of a
wave depends on
the medium.
• A medium is the substance that the
wave is traveling in or through.
23.
• In a given medium the
speed of the wave
remains the same, but
the frequency
increases and the
wavelength decreases.
24.
•Electromagnetic
waves (such as
visible light)
do NOT need a
medium.
25.
•The symbol c
stands for the
speed of light
which is known
to be equal to
8
3 x 10 m/s.
26.
• Pitch is determined by
frequency at which
sound waves strike your
ear drum.
• The higher the frequency
= higher the pitch
27.
• Doppler effect refers to a body
IN MOTION. When the object is
coming towards you, the
frequency is HIGHER than the
frequency when the object is
going AWAY . So when the
object is moving toward you
the sound has a HIGHER pitch
(due to higher frequency. *