Name: ________________________________________________ Date____________ Period_____
I. Calculating Frequency & Wavelength of EM radiation
A. Defining variables
a. Example:
What is the variable that we use to represent frequency (Hz)? = F (aka υ)?
b. What is the variable that we use to represent wavelength (m) = w
c. What is the variable that we use to represent
Speed of Light (m/s) = c
Note: all Electromagnetic Spectrum Waves travel at this same speed
d. Speed of light is a constant. How many m/s does light travel? 3.00*108
B. Deriving equations
Given the formula ……C = F*W (aka c = υ*λ)
1. What is the formula for calculating F (aka υ)? F = c/w
2. What is the formula for calculating W (λ)?
W = c/f
C. Calculating Frequency (F) and Wavelength (W)
Show your work! Use a calculator and do the actual math – don’t just leave the answer as a fraction!
1. Violet light has a wavelength of 4.10 x 10-12 m. What is the frequency?
f=c/w
=3.00*108/4.10x1012
= 0.73 x1020
=7.3*1019 Hz
2. Green light has a frequency of 6.01 x 1014 Hz. What is the wavelength?
f=c/w
=3.00*108/6.01x1014
=0.499*10-6 m
= 4.99*10-7 m
3. What is the wavelength (in meters) of the electromagnetic carrier wave transmitted by The Sports Fan radio
station at a frequency of 640 kHz?(Hint: convert kHz into Hz by multiplying by 103.)
f= 6.4x105
w=3.00x108/6.4*105
0.47 x 10(8-5) Hz
=0.47 x103 Hz
= 4.7x102 Hz
4. Calculate the wavelength of radiation with a frequency of 8.0 x 1014 Hz.
w=c/f
=3.00x108/8.0*1014
=0.375x10(8-14) m
=0.375x10-6 m
=3.75X10-7 m
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Name: ________________________________________________ Date____________ Period_____
II. Calculating Energy & Frequency of EM radiation
D. Defining variables
a. Frequency (Hz) = f
b. Energy (Joules) = J
c. Planck’s constant = h = 6.626 x 10-34 Joules*s
E. Deriving equations
Given the formula ……Energyphoton = h * F (aka Energyphoton = h * υ)?
a. What is the formula for calculating F (aka υ)? F = Energyphoton /h
F. Calculating Energy and Frequency (F)
Show your work!
1. Calculate the energy of a photon of radiation with a frequency of 8.5 x 1014 Hz.
Energyphoton = 8.5 x 1014 Hz x 6.626 x 10-34 Joules*s
= 56.321x10(14+-34)
=56.321x10-20 Joules
= 3.332x10-19 Joules
2. Calculate the energy of a gamma ray photon whose frequency is 5.02 x 1020 Hz?
Energyphoton = 5.02 x 1020 Hz x 6.626 x 10-34 Joules*s
= 33.2x10(20--34)
= 33.32x10(14+-34)
= 33.32x10-20 Joules
= 3.332x10-19 Joules
3. Calculate the energy of a photon of radiation with a wavelength of 6.4 x 10-7 m.
1st, need frequency
f= c/w= 3.00x108/6.4*10-7 =
.468 x 10*(8--7)
= .468x1015
= 4.68x1014 Hz
2nd, use 4.68x1014 Hz to calculate energy
Energyphoton = 4.68x1014 x 6.626 x 10-34 Joules
44.26168 x 10(14+-34) Joules
= 44.26168 x 10-20 Joules
= 4.426168 x 10-19 Joules
4. What is the energy of light whose wavelength is 4.06 x 10-11 m?
1st, need frequency
f= c/w
= 3.00x108/4.06*10-11
= .738 x 10*(8--11)
= .738 x 1019
= 7.38x1019 Hz
2nd, use this frequency to calculate for Energy
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Name: ________________________________________________ Date____________ Period_____
Energyphoton = 7.38x1019 x 6.626 x 10-34
= 48.89988 x 10(19+-34) Joules
= 48.89988 x 10-15
4.89988x10-14
G. General Knowledge
a. Rank these parts of the electromagnetic spectrum from lowest energy (1) to highest (7):
1Radio
2Infrared
3Visible
4Ultraviolet
5Microwave
6X ray
7Gamma
b. Rank these parts of the electromagnetic spectrum from lowest frequency (a) to highest (g):
1Radio
2Infrared
3Visible
4Ultraviolet
5Microwave
6X ray
7Gamma
c. Rank these parts of the electromagnetic spectrum from shortest wavelength (A) to longest (G):
1Gamma
2 X-ray
3Microwave
4Ultraviolet
5Visible
6Infrared
7Radio
d. 14. What is the relationship between frequency and wavelength?
(Direct or Inverse)
inverse
e.
What is the relationship between frequency and energy?
(Direct or Inverse) direct
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