Practice worksheet
1. Define wave crest, trough, amplitude, and wavelength.
Crest-top of a wave, trough- bottom of a wave, amplitude-height of wave from origin to crest or
origin to trough, wavelength-distance from crest to crest, trough to trough, or distance for one
complete cycle up and down of a wave.
2. Draw a wave and label it, using the following terms: crest, trough, amplitude, wavelength.
3. Draw a wave with a wavelength of 3.0 cm.
1.5
m
0m
3m
4. A cork floating on water moves up and down 10 times in 30 seconds. What is the frequency of the
water wave? F=cycles/s
f=10time/30s
f=.33 s-1
5. A tuning fork produces a sound of musical note middle C. It moves back and forth 256 times each
second. What is the frequency of the tuning fork? F=cycles/second
f=256times/s f=256s-1
6. What is the wavelength of sound waves having a frequency of 256 sec¯1. at 20 °C? Speed of sound =
340 m/sec c=v
340m/s=s-1
m/s/256s-1
=1.33m
7. What is the frequency of a sound wave with a wavelength of 1 meter at 20 °C?
c=v
v=c/
v=340m/s/1m
v=340s-1
8. What is the frequency of sound waves which have wavelengths of 6 cm when the air temperature is
20 °C?
v=c/
v=340m/s/(6cm/100)
v=5667s-1
9. What is the frequency of sound waves which have wavelengths of 12 meters when the air
temperature is 20 °C?
v=c/ 
v=340m/s/(12cm/100)
v=2833s-1
10. What is the electromagnetic spectrum? Shows the wavelengths, and frequencies of electromagnetic
radiation. Can be in increasing or decreasing order.
11. a. How are infrared waves different from red light waves? b. How are ultraviolet waves different
from violet light waves? c. In what ways are infrared, red, ultra-violet, and violet light waves alike?
a) Infrared waves have a smaller frequency and energy but longer wavelength than red light waves,
hence the INFRA- prefix
b) UV rays have a much greater frequency and energy but shorter wavelength than violet light waves,
hence the prefix ULTRAc) all are part of the electromagnetic spectrum. They all have characteristic wavelength, frequency, and
energy
12. What is the wavelength in meters of a radio wave with a frequency of 540,000 sec¯1.
3.0x108m/s/540,000s-1
C=c
=556m
13. The electromagnetic waves used in FM broadcasting by radio or television have frequencies of
approximately 100 megahertz. In standard AM radio broadcasting, the frequency is about 1 megahertz.
(Remember mega = 106.) Using the relationship λν = c, calculate the wavelengths used in AM and FM
broadcasting. FM:
c 3.0x108m/s/(100MHzX1x106Hz)
=3x1012m
AM:
c
3.0x108m/s/(1MHzX1x106Hz)
=3x1014m
14. Choose your favorite radio station. Using its frequency (ν), calculate its wavelength (λ). Be sure to
give the call letters of the station. Y95(95.3 on the FM dial) c

3.0x108m/s/(95.3MHzX1x106Hz)
=3.14x1012m
15. For each of the following wavelengths of visible light, determine the frequency and identify the
region of the electromagnetic spectrum to which it belongs. a. 2.0 x 10¯14 meterb. 4.0 x 10¯9 c. 6.0 x 10¯7
meter d. 1.00 meter
a) v=c/
v=3x108m/s/2.0x10-14m
v=1.5x1022s-1 so Gamma or Cosmic
b) v=c/
v=3x108m/s/4.0x10-9m
v=7.5x1016s-1 so UV rays
c) v=c/
v=3x108m/s/6.0x10-7m
v=5x1014s-1 so Infrared radiation
d) v=c/
v=3x108m/s/1.0m
v=3x108s-1 so btw radio and TV waves
16. For each of the following frequencies of visible light, determine the wavelength, and identify the
color of light assoicated with each frequency. a. 6.4 x 1014 sec¯1 b. 5.5 x 1014 sec¯1 c. 5.0 x 1014 sec¯1
a) c/v
=3x108m/s/6.4x1014s-1
x10-7m =467nm so blue
b)c/v
=3x108m/s/5.5x1014s-1
x10-7m =545nm so green
c)c/v
=3x108m/s/5x1014s-1
x10-7m =600nm so yellow
17. A chemist is using radiation with a frequency of 6 x 1013 sec¯1. a. What is the wavelength of this
radiation in meters? b. Identify this radiation as red, blue, infrared, ultraviolet, and so on. c. Estimate the
energy in kJ for one photon of this radiation. Plank's constant (h) is 6.63 x 10¯34 J sec. The velocity of light
is 3.00 x 108 meters/sec. Use the relationship E = hν.
a) c/v
=3x108m/s/6x1013s-1
x10-6m
b) Infrared since its exponent is 10-6m which is still in infrared. Visible is 10-7
c) E=hv so v=E/h and v=c/therefore: E/h=c/ cross multiply and E=hc so E=hc/
x10-34J*s x 3x108m/s)/5x10-6m
E=3.98x10-20J/photon
18. Use Plank's constant (6.63 x 10¯34 J sec) to determine the energy which corresponds to the following
frequencies of the values by 6.022 x 1023 photons/mole. a. 4.567 x 1014 hertz b. 6.165 x 1014 hertz c.
6.905 x 1014 hertz d. 7.307 x 1014 hertz e. 7.550 x 1014 hertz
a) E=hv
E=6.63x10-34J*s X 4.567x1014Hz
E=3.03x10-19J/photon
b) E=hv
E=6.63x10-34J*s X 6.165x1014Hz
E=4.08x10-19J/photon
c) E=hv
E=6.63x10-34J*s X 6.905x1014Hz
E=4.58x10-19J/photon
d) E=hv
E=6.63x10-34J*s X 7.307x1014Hz
E=4.84x10-19J/photon
e) E=hv
E=6.63x10-34J*s X 7.550x1014Hz
E=5.01x10-19J/photon