1. DO NOW – on loose-leaf
Question: How many waves are involved in this story?
Imagine that your family has just returned home from a day at the beach. You had fun playing in the ocean under a hot sun. You put some cold pizza in the microwave for dinner, and you turn on the radio. Just then, the phone rings. It’s your friend calling to ask about homework.

2. Answer 1. Ocean waves 2. Light waves from the sun 3. Microwaves
4. Radio waves
5. Sound waves (from the radio, telephone and voices).

3. Missing Work A2/3 Missed Tests: Anthony, Nysier
Missing Rolling Ball Labs:
Everyone BUT Autumn, Diana, Parisa
You have until Friday to turn this in for any credit!
Did you finish your Achieve Article?

4. Missing Work A5/6 Missed Tests: Malik, Traeona, Khai, Tyree,
Taheera, Deandre, Jada
Missing Rolling Ball Labs:
Everyone BUT Anthony, Jada, Sumayya
You have until Friday to turn this in for any credit!
Did you finish your Achieve Article?

5. Missing Work B2/3
Missed Tests: Cordell, Ramen, Imani, Jannie, Saddiq, Khariah, Kimani
Missing Rolling Ball Labs:
Everyone BUT Robert Davis
You have until Friday to turn this in for any credit!
KIM Sheets DUE TODAY

6. Agenda for Tuesday April 21 2015
Topic: Types of Waves
Objective: SWBAT analyze info in different formats IOT distinguish between types of waves and describe their properties
Agenda
Do now
Notes
Guided Practice
Graphic Organizer
Exit Ticket

7. Types of Waves
Chapter 14, Section 1

8. What is a Wave?
A disturbance that transfers energy through matter or empty space
Energy moves from one place to another
Matter does not move from one place to another, just energy (ex. ocean waves)

9. CHECKING FOR UNDERSTANDING
TRUE OR FALSE – Waves carry matter over great distances
FALSE – Waves transfer energy, not matter

10. Medium
Definition: A substance that a wave travels through (liquid, solid or gas)
Waves that need a medium = MECHANICAL WAVES (ex. sound, ocean, earthquakes)

11. CHECKING FOR UNDERSTANDING
If there is an explosion in space, could you hear it?
No, because space is a vacuum and there is no medium (air) for the sound waves to travel through.

12. Electromagnetic Waves
Waves that consist of changing electric and magnetic fields; moves at the speed of light
Do not need a medium (ex – Sun produces visible light, which travels through space)
Visible light, X-rays, Microwaves, TV & Radio Signals

13. CHECKING FOR UNDERSTANDING
If there were a radio station on mars, could you possibly tune in here on Earth?
Yes, if the signal were strong enough, because radio waves are electromagnetic and do not require a medium (air) to travel through.

14. Waves transfer energy
Waves do work on objects (ex. Wave hitting the beach)
The bigger the wave, the more energy it carries
As the wave travels, the circles (wave front) get larger, and energy spreads out over a larger area

15. Vibrations & Waves Most waves are caused by vibrating objects
Periodic Motion – Motion that repeats itself
Simple Harmonic Motion – repeating motion in a symmetrical path around a central position (equilibrium)

16. Two types of Waves
TRANSVERSE WAVES
LONGITUDINAL WAVES

17. TRANSVERSE WAVES
Waves vibrate in an up and down motion in perpendicular motion
Particles move up and down
CREST
TROUGH

18. LONGITUDINAL WAVES Waves move back and forth in a parallel motion
Particles move back and forth
Compressions
Rarefactions
Example: SOUND WAVE

19. Surface Waves
Occur at the boundary between two different mediums (ex – water and air)
Transverse Wave + Longitudinal Wave = Surface Wave

20. Guided/Independent Practice
Give two similarities and one difference between mechanical waves and electromagnetic waves.
Answer:
Both mechanical and electromagnetic waves carry energy from place to place, and both can travel through a medium. Mechanical waves require a medium to travel through, but electromagnetic waves do not.

21. Guided/Independent Practice
2. Why can light travel through outer space, but sound cannot? Answer: Sound waves are mechanical waves. They require a medium to travel through. There is almost no matter in outer space, so mechanical waves cannot travel through space. Light is an electromagnetic wave. Electromagnetic waves do not require a medium to travel, so they can move through outer space.

22. Guided/Independent Practice
3. What is the difference between how transverse waves and longitudinal waves move particles? Answer: Transverse waves cause particles to vibrate perpendicular to the direction in which the wave is traveling. Longitudinal waves cause particles to vibrate parallel to the direction in which the wave is traveling.

23. Guided/Independent Practice
4. A student is describing a longitudinal wave in his notebook. He writes down “The distance between crests is 3 cm.” What is wrong with what the student recorded? Answer: The student recorded data about crests, but longitudinal waves do not have crests.

24. Guided/Independent Practice
5. Why does a noise sound fainter as you move away from its source? Answer: The energy in the wave is spread out over a larger area, so the amount of energy in the wave at any given point is lower.

25. Exit Ticket Quiz What does a wave carry through matter or space?
T or F: Most waves are caused by vibrating objects.
Give one example of each of the following:
-Mechanical Wave
-Electromagnetic Wave
-Transverse Wave
-Longitudinal Wave

26. Graphic Organizer
Directions: Using your notes and Ch. 14, Sec. 1 of your textbook, complete the graphic organizer below.