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!!

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.

12/8-9 Space Mission Poster 115-116 12/10-11 Travel Brochure 117-118 Table of Contents Date Lecture/ Activity/ Lab Page 11/16 Solar System 99-100 11/17-19 Solar System Web 101-102 11/30 Planetary Soda Pop 103-104 12/1 Conditions for Life 105-106 12/2 Space Mission Notes 107-108 12/3 Lost on the Moon 109-110 12/4 Solar System with Writing 111-112 12/7 Cosmic Quest 113-114 12/8-9 Space Mission Poster 115-116 12/10-11 Travel Brochure 117-118 12/14 Early Astronomers 119-120 12/15 Light Years 121-122 1/5 Formation of the Universe 123-124 1/6 Waves and the EM Spectrum 125-126

Waves- Energy and Motion

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.

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.

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

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.

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.

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.

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

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.

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

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.

What do you know about waves? M M M

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.

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

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

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

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 .

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.

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!!