FF Read each question and circle the best answer: 1. Waves interact and behave in many different ways. Circle all​ ​of​ ​the​ ​following​​that are wave behaviors. a. Absorption b. Transmission c. Interference d. Diffusion 2. Mr. Shuler is wearing a white shirt. What wave property causes us to see his shirt as white? a. All of the wavelengths of light are reflected b. All of the wavelengths of light are absorbed c. His shirt is made white d. The white is the only wavelength transmitted.

3. Chris is listening to music with his noise canceling headphones, so he does not hear the talking around him. What type of interference are his headphones providing? a. Constructive interference b. Destructive interference c. General interference d. No interference

4. Which of the following describes looking at an object through translucent material? a. You see the object clearly but it is upside down b. You do not see the object at all c. You see the object but its details are blurry d. You see the object very clearly 5. Why can’t you see your reflection in a brick wall? a. Light rays are reflected in only one direction from the rough service b. No light is reflected from a brick wall c. Light rays are reflected in many directions from the uneven surface d. Reflection of light from a rough surface is regular reflection

Essential Question What misconceptions did I have in 8.P.3A.1, 8.P.3A.2, and 8.P.3A.3 that caused me confusion on the test?

OBJECTIVE 1. GO OVER FF & EQ 2. GO OVER TEST 3. PASS OUT PAPERS

Falcon Focus Read each question and circle the best answer: 1. A student places a sheet of black construction paper on her desk. What happens to most of the light that strikes the black construction paper? a. The light is bent by the paper b. The light reflects off the paper c. The light is absorbed by the paper d. The light passes through the paper   2. Suzie wakes up on a sunny but cool day and can choose to wear a T-Shirt in one of the following four colors: black,​ ​pink, white​ ​and​ ​yellow.​ She decides to wear the black​ ​T- shirt​ because it will take in more of the sun’s light than the other T-shirts. Which property of light is she using to stay warm? a. Absorption b. Brightness c. Reflection d. Refraction

3. Which of these effects does a prism have on light? a. It reflects the light b. It refracts the light c. It focuses the light d. It absorbs the light   4. ) Which of the following explains why an apple looks red? a. The apple is reflecting red light and absorbing all other colors of light b. The apple is absorbing red light and reflecting all other colors of light c. The apple is absorbing all colors of light, but absorbs the red light better d. The apple is reflecting all the light

5. A sound wave is produced in a metal cylinder by striking one end 5. A sound wave is produced in a metal cylinder by striking one end. Which of the following occurs as the wave travels along the cylinder? a. Its amplitude increases b. Its frequency increases c. It transfers matter d. It transfers energy

Essential Question What happens when waves interact with one another?

Falcon Focus How are the following pairs of terms different? Diffraction and refraction. Convex Mirror and Convex Lens Concave mirror and Concave Lens Node and Antinode Essential Question: How would you compare constructive and destructive interference of a wave?

Objective 1. Go over FF & EQ 2. Complete 3-5 test questions 3. Complete the Interference Exploration 4. Finish Taking Notes on Interference 5. Complete the Characteristic of Behavior Waves Activity Sheet 6. Pass Out papers

Test Questions

Question 17 A property of wave is an important measurements of sound. It explains how fast the sound waves are oscillating. It is different than how fast the wave travels through the medium. The faster the sound wave oscillates the higher pitch it will have. For example, on a guitar a big heavy string will vibrate slowly and create a low sound or pitch. A thinner lighter string will vibrate faster and create a high sound or pitch. The pitch of a musical sound depends on the sound wave's (8.P.3.A.3)   a. wavelength. b. frequency. c. speed. d. amplitude.

Question 18 A skipper on a boat notices wave crests passing the anchor chain every 5 s. The skipper estimates the distance between crests is 15 m. What is the speed of the water waves?  (8.P.3.A.3)   A) 3 m/s  B) 15 m/s  C) 5 m/s  D) not enough information given

Question 19 19. The amplitude of a particular wave is 1 m. The top to bottom ( crest to trough) distance of the wave is (8.P.3.A.3) a. 0.5 m. b. 1 m. c. 2 m. d. 2.5m

Question 20 From Figure 2 above, which letter shows the area of compression for the sound created by the tuning fork? (8.P.3.A.2)   a. a. b. b. c. c. d. d.

QUESTION 21 Which of the following statements illustrates the concept that waves carry energy from one place to another: (8.P.3.A.1)   a. Ocean waves may cause boats to tip over. b. Sunlight heats the surface of the earth. c. Seismic waves cause earthquake damage. d. All of the statements illustrate the concept.

QUESTION 22 A wave with a frequency of 14 Hz has a wavelength of 3 meters. At what speed will this wave travel? (8.P.3.A.2)   42 m/s 4.67 m/s 0.2 m/s 4.67 m

QUESTION 23 The speed of a wave is 65 m/sec. If the wavelength of the wave is 0.8 meters, what is the frequency of the wave? (8.P.3.A.2)   52 m/s 52 Hz 81.25 Hz 81.25 m/s

QUESTION 24 What would be the period for question 23? (8.P.3.A.2)   52s 81.25s 0.019s 0.012s

QUESTION 25 A wave with a frequency of 500 Hz is traveling at a speed of 200 m/s. What is the wavelength? (8.P.3.A.2)   W=v/f 200m/s / 500 (1/s) 100,000 m 0.4 m 2.5m 100,000m/s

Step 1 Turn to page 68-69 in your interactive science notebook to complete the following on another sheet a of paper. 1. What is interference? 2. What is constructive interference? 3. What is destructive interference?

Watch the video

Explore Activity Wave Interference Complete the activity and complete the questions under Think If Over. Also answer the following questions from pages 68-69. 4. How would you illustrate and explain diagram 2 on page 68. 5. How would you illustrate and explain diagram 2 on page 69.

BEHAVIOR OF WAVES Standard 8.P.3 Students will demonstrate an understanding of the properties and behaviors of waves. Performance Indicator
8.P.3A.4 Analyze and interpret data to describe the behavior of mechanical waves as they intersect.

Interference Waves interfere with each other. Interference is the interaction between waves that meet. The extremes of what can happen are called constructive interference and destructive interference

CONSTRUCTIVE INTERFERENCE Interference may be constructive: ○  A crest will interfere with another crest constructively to produce a larger crest and a trough will interfere to produce a larger trough. ○  Compressions interfere constructively with each other as do rarefactions. Constructive Interference – 2 waves combine to form a new wave with a larger amplitude.

CONSTRUCTIVE INTERFERENCE

DESTRUCTIVE INTERFERENCE Interference may be destructive: ○ A crest will interfere with a trough to lessen or cancel the displacement of each. Compressions interfere with rarefactions to lessen or cancel the displacement of each. Destructive Interference – 2 waves combine to produce a wave with a smaller amplitude.

Interference http://www.olympusmicro.com/primer/java/interference/index.html

Constructive and Destructive Algebraic Addition (in phase) Partially Constructive (somewhat out of phase) Destructive (180° out of phase) S S Non-coherent signals (noise)

SOUND WAVES Sound waves interfere with each other changing what you hear. ○  Destructive interference makes sounds quieter; constructive interference makes sounds louder. ○  Sound waves reflect in tubes or some musical instruments to produce standing waves which reinforce sound through constructive interference to make the sound louder.

PITCH is the human perception of frequency. How high or how low a sound seems to be depends on frequency. High notes have high frequencies, and low notes have low frequencies.

Left person hears lower f due to longer λ. The Doppler effect can be described as the effect produced by a moving source of waves in which there is an apparent upward shift in frequency for observers towards whom the source is approaching and an apparent downward shift in frequency for observers from whom the source is receding. Left person hears lower f due to longer λ. Sound source moving with vs Apparent f0 is affected by motion. Right person hears a higher f due to shorter λ.