1. Intro to Light: Electromagnetic Waves Standard: Describe the properties and uses of forms of electromagnetic radiation from radio frequencies through gamma radiation.
Warm up
What is the main difference between mechanical and electromagnetic waves?

2. 5 Facts about light What is Light? The EM wave Speed of light
The EM spectrum
Calculations

3. 1. What is Light?
Definition of Light: A visible range of the electromagnetic spectrum that can be detected by the human eye.

4. 2. The Electromagnetic Wave
2) Light requires no medium to travel
Can go through gases and transparent/translucent liquids and solids.
Transverse energy move perpendicular to the direction the wave moves
In addition, electric and magnetic fields are at right angles (90 degrees) to each other
Electric Field
Direction of travel towards you
Magnetic Field

5. 3. The speed of Light
All electromagnetic waves travel at 3.0 x 108 m/s
That means you would be able to leap/run/skip 300 million meter sticks in only one second!

6. Activity 1
Label all the parts of the electromagnetic spectrum in order of increasing frequency.
Radio Waves, Microwaves, Infrared, Visible Light, Ultra Violet, X-rays, Gamma Rays
Label the trend arrows as well
Wavelength ___________
Frequency __________
Energy ___________
More _________ and___________
Velocity=____________________________

7. 4. The Electromagnetic Spectrum

8. 4. The Electromagnetic Spectrum
4 Visible Light
1 Radio waves
2 Microwaves
3 Infrared
5 Ultra Violet
6 X-Rays
7 Gamma Rays
Wavelength (λ) Decreases
Frequency (f) Increases
Energy (E) Increases
More Penetration and Dangerous

9. 4. The Electromagnetic Spectrum
Wavelength (λ) Decreases
Frequency (f) Increases
Energy Increases
3.0 x 108 = λ • f
V = λ • f
More Penetration and Dangerous
Velocity = 3.0 x 108 m/s
For All Electromagnetic Waves

10. 5. Speed of light distance-time calculations
V = λ • f
5. Speed of light distance-time calculations
Velocity = 3.0 x 108 m/s for all electromagnetic waves
If you experience any of these you have an electromagnetic wave and v = 3.0 x 108 m/s
Radio Waves, Microwaves, Infrared, Visible Light, Ultra Violet, X-rays, Gamma Rays

11. Example 1
What is the frequency of an electromagnetic wave if it has a wavelength of 1.0 km?

12. Example 1
What is the frequency of an electromagnetic wave if it has a wavelength of 1.0 km?

13. Example 2
How long does it take for light from the sun to reach Earth if the sun is 1.5 x 1011 m away?

14. Example 2
How long does it take for light from the sun to reach Earth if the sun is 1.5 x 1011 m away?

15. Example 3
The AM radio band extends from 5.4 x 105 Hz to 1.7 x 106 Hz. What are the longest and shortest wavelengths in this frequency range?

16. Example 3
The AM radio band extends from 5.4 x 105 Hz to 1.7 x 106 Hz. What are the longest and shortest wavelengths in this frequency range?

17. Exit
What is the relationship between the wavelength versus the frequency in the electromagnetic spectrum?