17.1 Mechanical Waves FRIDAY, APRIL 8, 2011 NO OPENER TODAY... PICK UP TEST ANSWERS AND QUESTIONS TO COMPLETE ESSAY PORTION OF TEST IF NOT COMPLETED YESTERDAY

17.1 Mechanical Waves

FRIDAY, APRIL 8, 2011NO OPENER TODAY...PICK UP TEST ANSWERS AND QUESTIONS TO COMPLETE ESSAY PORTION OF TEST IF NOT COMPLETED YESTERDAY. You get 20 minutes if needed to complete.

As soon as you are finished with the test, you will start the computer simulation lab on waves (sound and light)... It will be helpful to have earbuds today and all next week.Download from podcast page, to get quick link. Paper instructions are at desk to leave each period.

If you are working in groups, be sure you convert you egg drop video into a movie and submit to my drop box as soon as you can...

We are not working on iMovie projects today in class except to convert or to submit.(6th period isn’t doing iMovie project.)

Our next unit is waves, sound, light, doppler effect, etc. Pre-AP chapter 17-18-19Regular Chapters 14-15...HOMEWORK: START READING CH. 14 REG (CH. 17 PAP)...


Monday, April 11, 2011 - Opener #5B (5th-6th-7th periods)Use sentences.1. What are at least 5 different type of waves? Hint: think about 3 from computer lab.2. How would you describe frequency and amplitude in your own words from what you have learned so far in the computer lab or from previous 8th grade standards?3. Describe a real-life experience you have had with waves (such as riding a wave, creating waves, noticing waves, capturing waves...)

CW: Complete and turn in computer wave simulation lab. Answers should be on your own paper.CW: Start Notes on waves. Complete all of section 1 and at least start section 2 notes.

Earbuds are needed all week.Pizza Party upcoming ... HW: PAP: Read ch. 17 REG: Read ch. 14 by Tuesday...HW PAP: Submit iMovie Project by Friday, April 15th...HW REG: 3rd/4th periods - Submit projects as you complete outside of class...


Tuesday, April 11, 2011 - Opener #5B or #6 (same opener as yesterday for 5th-7th)Use sentences.1. What are at least 5 different type of waves? Hint: think about 3 from computer lab.2. How would you describe frequency and amplitude in your own words from what you have learned so far in the computer lab or from previous 8th grade standards?3. Describe a real-life experience you have had with waves (such as riding a wave, creating waves, noticing waves, capturing waves...)

CW: Complete and turn in computer wave simulation lab. Answers should be on your own paper.CW: Start Notes on waves. Complete all of section 1 and at least start section 2 notes.

Earbuds are needed all week.Pizza Party upcoming ... REG: Read ch. 14 by tomorrowHW PAP: Submit iMovie Project by Friday, April 15th...HW REG: 3rd/4th periods - Submit projects as you complete outside of class...


Tuesday, April 11, 2011 - Opener #5B or #6 (same opener as yesterday for 5th-7th)Use sentences. - 5th-7th periods...1. What are at least 5 different type of waves? Hint: think about 3 from computer lab.2. How would you describe frequency and amplitude in your own words from what you have learned so far in the computer lab or from previous 8th grade standards?3. Describe a real-life experience you have had with waves (such as riding a wave, creating waves, noticing waves, capturing waves...)

CW: Complete and turn in computer wave simulation lab IN BOX. Answers should be on your own paper.CW: Complete all of section 1 and at least start section 2 notes if not done yesterday.CW: PAP 5th & 7th periods - Start and complete NOTES 17.3 and 17.4 abbreviated... Be sure to watch all videos and to do the interactive quick activity with link connection.Earbuds are needed all week.Pizza Party upcoming ... HW: PAP - Wave calculations worksheet - side 1 due tomorrow... You can also do side 2 but will be due later... (6th period - side 1 is due Thursday.)CW/HW PAP only: Ch. Review pg. 527-528 #1-24, 29-34 AND pg. 529 #1-6 due Friday.HW PAP: Submit iMovie Project by Friday, April 15th...


What causes mechanical waves?

What Are Mechanical Waves?

A mechanical wave is created when a source of energy causes a vibration to travel through a medium.


In a wave pool, the waves carry energy across the pool. You can see the effects of a wave's energy when the wave lifts people in the water.


play the CBS News Videoclip on Chile Earthquake & Tsunami

REAL PLAYER downloads...

QuickTime™ and a decompressor

are needed to see this picture.


QuickTime™ and a decompressor

are needed to see this picture.


A mechanical wave is a disturbance in matter that carries energy from one place to another.

• Mechanical waves require matter to travel through.• The material through which a wave travels is called a

medium.• Mechanical waves require a medium to travel through. Ex.

Solids, liquids, and gases all can act as mediums. • A mechanical wave is created when a source of energy

causes a vibration to travel through a medium.• A vibration is a repeating back-and-forth motion.

What Are Mechanical Waves?


What are the three main types of mechanical waves?

Types of Mechanical Waves

The three main types of mechanical waves are transverse waves, longitudinal waves, and surface waves.Mechanical waves are classified by the way they move through a medium.

The following link demonstrates 4 wave types relative to particle & energy movement... CLICK HERE TO SEE A QUICK ILLUSTRATION.http://paws.kettering.edu/~drussell/Demos/waves/wavemotion.html

http://paws.kettering.edu/~drussell/Demos/waves/wavemotion.html

Copyright © by Holt, Rinehart and Winston. All rights reserved.

ResourcesChapter menu

Transverse Wave

Section 1 Types of WavesChapter 17

Click below to watch the Visual Concept.

Visual Concepthttp://my.hrw.com/sh/hk6_0030390966/student/ch14/sec01/vc03/hk614_01_v03fs.htm

http://my.hrw.com/sh/hk6_0030390966/student/ch14/sec01/vc03/hk614_01_v03fs.htm



Transverse WavesWhen you shake one end of a rope up and down, the vibration causes a wave.

• The highest point of the wave is the crest.• The lowest point of the wave is the trough.• A single point on the rope vibrates up and

down between a crest and trough.



A transverse wave is a wave that causes the medium to vibrate at right angles to the direction in which the wave travels.

The wave carries energy from left to right, in a direction perpendicular to the up-and-down motion of the rope.

Other examples: shaking a blanket... rope on doorknob shaking up and down..., light waves



A transverse wave causes the medium to vibrate in a direction perpendicular to the direction in which the wave travels.


CrestDirection of wave

Rest position

Direction of vibration

Trough



Longitudinal Wave







Longitudinal WavesA longitudinal wave is a wave in which the vibration of the medium is parallel to the direction the wave travels. ex. slinky, sound waves, P-waves by earthquakes...

In a spring toy, the wave carries energy along the spring.

• An area where the particles in a medium are spaced close together is called a compression.

• An area where the particles in a medium are spread out is called a rarefaction.



A. A compression starts to move along the spring.

B. A rarefaction follows the compression along the spring.


Push

Pull

Compression

Direction of wave

Rarefaction

Compression

Rest position


As compressions and rarefactions travel along the spring, each coil vibrates back and forth around its rest position.




Formation and Movement of Ocean Waves







Surface WavesOcean waves are the most

familiar kind of surface waves.

A surface wave is a wave that

travels along a surface separating two media.

•In a surface wave, particles move in circles.• Surface waves occur at the boundary between

two different mediums, such as between water and air.

• The particles move both perpendicularly and parallel to the direction that the wave travels.

Types of Mechanical WavesQuickTime™ and a

decompressorare needed to see this picture.

WAIT FOR VIDEO BEFORE CLICKING PAST “PARALLEL” LINE..

MORE PEOPLE WERE KILLED IN THIS TSUNAMI THAN LIVE IN ALL OF LITTLE ROCK


As the ocean wave moves to the right, the bobber moves in a circle, returning to its original position.

Types of Mechanical Waves Wave direction


The bobber helps to visualize the motion of the medium.

• When a crest passes the bobber, the bobber moves up. When a trough passes, the bobber moves down.

• The bobber also is pushed back and forth by the surface wave, like the motion of a longitudinal wave.

• The two motions combine, and the bobber moves in a circle.



Assessment Questions - ANSWER these questions then continue with Notes 17.2

1. A mechanical wave carries energy from one place to another through the a. physical transfer of matter.

b. interaction of electromagnetic fields.

c. phase changes of a medium.

d. vibration of a medium.


Assessment Questions

1. A mechanical wave carries energy from one place to another through the a. physical transfer of matter.

b. interaction of electromagnetic fields.

c. phase changes of a medium.

d. vibration of a medium.

ANS: D



2. In what type of wave is the vibration of the medium parallel to the direction in which the wave travels?a. transverse waveb. longitudinal wavec. surface waved. rarefaction



2. In what type of wave is the vibration of the medium parallel to the direction in which the wave travels?a. transverse waveb. longitudinal wavec. surface waved. rarefaction

ANS: B



3. An example of a transverse wave is a(n) a. sound wave traveling through air.

b. ocean wave far from the shore.

c. ocean wave as it approaches the shore.

d. light wave traveling through space.



3. An example of a transverse wave is a(n) a. sound wave traveling through air.

b. ocean wave far from the shore.

c. ocean wave as it approaches the shore.

d. light wave traveling through space.

ANS: D



1. As a surface wave travels across water, molecules of water move in a circular pattern.

TrueFalse



1. As a surface wave travels across water, molecules of water move in a circular pattern.

TrueFalse

ANS: T


Continue with 17.2 properties of waves lesson for notes...

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17.1 Mechanical Waves FRIDAY, APRIL 8, 2011 NO OPENER TODAY... PICK UP TEST ANSWERS AND QUESTIONS TO COMPLETE ESSAY PORTION OF TEST IF NOT COMPLETED YESTERDAY