1. Practice/Application: Notes
Waves and the EM Spectrum
125
Waves and the EM Spectrum
126
1/6/16
2/22-25/2013
2/22-25/2013
1/6/16
EQ: How can patterns be used to describe the universe?
Practice/Application:
Notes
Starter/Practice:
When looking at the night sky, Shrek tells Donkey, “The stars don’t tell us our future, but our past.” Do you agree or disagree? Why? Please explain your thoughts on this. Use what you learned in your notes!!!
Connection/Exit:
Describe what you have learned about the EM spectrum. Please write 3-4 sentences!!

2. 1. Starter 2. Activity 3. Notes 4. Exit
January 6, 2016 AGENDA Objective 8.8C Explore how different wavelengths of the electromagnetic spectrum such as light and radio waves are used to gain information about distances and properties of components in the universe by completing notes.

3. 12/8-9 Space Mission Poster 115-116 12/10-11 Travel Brochure 117-118
Table of Contents
Date Lecture/ Activity/ Lab Page
11/ Solar System
11/ Solar System Web
11/ Planetary Soda Pop
12/ Conditions for Life
12/ Space Mission Notes
12/ Lost on the Moon
12/ Solar System with Writing
12/7 Cosmic Quest
12/8-9 Space Mission Poster / Travel Brochure
12/ Early Astronomers
12/ Light Years
1/ Formation of the Universe
1/ Waves and the EM Spectrum

4. Waves- Energy and Motion

5. Waves
A wave is a back and forth motion or disturbance that carries energy progressively from point to point.
The two types of waves are mechanical or electromagnetic.

6. Media or Medium Media is material that waves are able move through.
Medium- one type of media.
Solids like table, earth, and walls.
Liquids like water.
Gas like the air we breathe.

7. Amplitude
A. Amplitude- a measure of the wave’s height. Waves with larger amplitudes carry more energy. Think Tsunami…

8. Wavelength
B. Wavelength- the distance from one point on a wave to the corresponding point. It is common to mark from crest to crest or trough to trough.

9. Trough, Crest and Wave height
C. Trough- the lowest points in the wave. D. Crest- the highest points in the wave. E. Wave height- the measure of the height of the wave from top to bottom.

10. Frequency
F. Frequency- the number of waves that pass a point in a given amount of time. Frequency is measured in Hertz (Hz).
1Hz = one wave per second.

11. Period
G. Period - the time it takes the waves to move. Period is measured in seconds (s), minutes (min ) or Hours (h).
0.5 s G

12. Frequency Vs. Period Frequency Period
Frequency refers to how often something happens.
Frequency is a rate quantity.
Period refers to the time it takes something to happen.
Period is a time quantity.
If the woodpecker drums upon a tree 2 times in one second, then the frequency is 2 Hz. Each drum must endure for one-half a second, so the period is 0.5 s.
If the woodpecker drums upon a tree 5 times in one second, then the frequency is 5 Hz; each drum must endure for one-fifth a second, so the period is 0.2 s.

13. Mechanical Waves
Mechanical waves travel and create vibrations through media (material including solid, liquid, gas, or combination).
Examples are sound, seismic and water waves.

14. Electromagnetic Waves
EM Waves travel through empty space and do not need a medium in which to travel
Examples of EM waves are: microwaves, radio waves, x- rays, and visible light.
The most important properties are frequencies and wavelength.

15. What do you know about waves?M M M

16. Radio Waves & Microwaves
Long wavelengths; low energy.
Radio and television stations broadcast using radio waves.
Microwaves
Shorter wavelengths and more energy than radio waves.
The waves cause water to vibrate; this energy gives off thermal energy.

17. Infrared waves Infrared Radiation (IR)
slightly lower energy than visible light
can increase the thermal energy of objects
Used by sensors in satellites and planes to gather information. Emitted by the sun, stars, and planets

18. Visible Light Visible Light small part of the EM spectrum we can see
ROY G. BIV - colors in order of increasing energy
Used to help determine star’s temperature R O Y G. B I V
red
orange
yellow
green
blue
indigo
violet

19. Ultraviolet Rays Ultraviolet Radiation (UV)
slightly higher energy than visible light
Types:
UVA - tanning, wrinkles
UVB - sunburn, cancer
UVC - most harmful, sterilization

20. X- rays X rays higher energy than UV; short wavelengths
can penetrate soft tissue, but not bones
Hot gases in the Universe also emit X-rays .

21. Radiation treatment using radioactive cobalt-60.
Gamma Rays
Gamma rays
highest energy EM radiation; shortest wavelengths
emitted by radioactive atoms
used to kill cancerous cells
Radiation treatment using radioactive cobalt-60.

22. Practice/Application: Notes
133
Waves and the EM Spectrum
134
Waves and the EM Spectrum
1/7/15
2/22-25/2013
2/22-25/2013
1/7/15
Practice/Application:
Notes
Starter/Practice:
When looking at the night sky, Shrek tells Donkey, “The stars don’t tell us our future, but our past.” Do you agree or disagree? Why? Please write at least ¾ page explaining your thoughts. Use what you learned in your notes!!! I WILL give you paper to write on.
Connection/Exit:
Describe what you have learned about how astronomers determine the composition of stars. Please write 3-4 sentences!!