Oct. 4, 2012PG. #38 Focus: Introduction to Waves

Oct. 4, 2012 PG. #38Focus: Introduction to WavesObjective: #6.P.1.1, identify the basic

characteristics of a transverse waveHW: enter important words and their

definitions into your glossary, background research

Warm-Up: Wave Brainstorm

What do you know about waves?

Pg. 37– Important Words to Knowatom, proton, electron, neutron, nucleus, atomic mass, atomic number, wave, amplitude, frequency, crest, trough

How am I doing?

• Record Atom Quiz Grade

At the end of today:You will be able to answer this question:

What is Wave A’s amplitude and frequency compared to Wave B?

-2

-1

0

1

2

0 5 10 15

B

A

But why do I care, Ms. Torres?

Waves transfer sound and light. Without them, you wouldn’t SEE or HEAR anything!A world without waves would be a dark, silent place.

Vocabulary to Know

What is a wave?

A wave is a type of energy.Waves transfer sound and light.

Examples:In the Ocean In the Clouds Earthquake

What do we call the tops and bottoms of waves?

The top of the wave is the CREST. The bottom of the wave is the TROUGH.

Vocabulary to Know

CREST

TROUGH

What is amplitude?

Amplitude is the height of the wave. It is how high and how low the waves go.

Vocabulary to Know

How high

does it

go?

How low does it go?

What is frequency?

Frequency is the number of crests OR troughs in a given space or time.

Vocabulary to Know

How many troughs?http://id.mind.net/~zona/mstm/physics/waves/introduction/introductionWaves.html

How many crests?

3

3

How would you explain to a first grader?

Wave?

Amplitude?

Frequency?

Example #1Which wave has a higher amplitude?

Which wave has a lower amplitude?

-2

-1

0

1

2

0 5 10 15

A

B

1 Wave A has a higher amplitude.

Wave B has a lower amplitude.

Example #2Which wave has a higher amplitude?

Which wave has a lower amplitude?

-2

-1

0

1

2

0 5 10 15

A

B

2 Wave B has a higher amplitude.

Wave A has a lower amplitude.

Example #3Which wave has the highest amplitude?

Which wave has the lowest amplitude?

-2

-1

0

1

2

0 5 10 15

A

B

C

3 Wave A has the highest amplitude.

Wave C has the lowest amplitude.

Example #4Which wave has a higher frequency?

Which wave has a lower frequency?

-2

-1

0

1

2

0 5 10 15

A B

4 Wave A has a higher frequency.

Wave B has a lower frequency.

Example #5Which wave has a higher frequency?

Which wave has a lower frequency?

-2

-1

0

1

2

0 5 10 15

AB

5 Wave B has a higher frequency.

Wave A has a lower frequency.

Example #6Which wave has the highest frequency?

Which wave has the lowest frequency?

-2

-1

0

1

2

0 5 10 15

CB

6

A

Wave A has the highest frequency.

Wave C has the lowest frequency.

Example #7Which wave has the highest amplitude?

Which wave has the lowest frequency?

-2

-1

0

1

2

0 5 10 15

B

7 A Wave A has the highest amplitude.

Wave B has the lowest frequency.

Example #8Which wave has the highest frequency?

Which wave has the lowest amplitude?

-2

-1

0

1

2

0 5 10 15

B

8

A

Wave A has the highest frequency.

Wave A has the lowest amplitude.

Example #9Which wave has the highest frequency?

Which wave has the lowest amplitude?

-2

-1

0

1

2

0 5 10 15

CB

9 Wave B has the highest frequency.

Wave C has the lowestamplitude.

Example #10Which wave has the highest frequency?

Which wave has the lowest amplitude?

-2

-1

0

1

2

0 5 10 15

A

B

10 Waves A

and B have the same frequency.

Wave B has the lowestamplitude.

Comparing Waves

Let’s go back and write comparison statements for each example.

Comparison statements answer this question:

What is Wave A’s amplitude and frequency compared to Wave B?

Example #1What is wave A’s amplitude and frequency in comparison to wave B?

-2

-1

0

1

2

0 5 10 15

A

B

1 Wave A has a higher amplitude than Wave B because it has higher and lower curves than Wave B. Wave A has the same frequency as Wave B because it has the same number of hills as Wave B.

Example #4What is wave A’s amplitude and frequency in comparison to wave B?

-2

-1

0

1

2

0 5 10 15

A B

4 Wave A has the same amplitude as Wave B because their crests are the same height. Wave A has a higher frequency than Wave B because it has a higher number of humps than Wave B.

Example #7What is wave A’s amplitude and frequency in comparison to wave B?

-2

-1

0

1

2

0 5 10 15

B

7 AWave A has a higher amplitude than Wave B because its humps are higher and lower than Wave B’s. Wave A has a higher frequency than Wave B because it has a higher number of humps than Wave B.

Example #9What is wave C’s amplitude and frequency in comparison to wave B?

-2

-1

0

1

2

0 5 10 15

CB

9Wave C has a lower amplitude than Wave B because its humps are not as high and low as Wave B’s. Wave C has a lower frequency than Wave B because it has a lower number of humps than Wave B.