1. Science 8 Module J Unit 1 Lesson 1 Waves

2. Waves- a disturbance that transfers energy from one place to another Medium- the material through which a wave travels Longitudinal wave- particles move back and forth or parallel to the wave (sound) Transverse wave- particles move perpendicularly to the direction the waves travel (water) Mechanical wave- can travel through more than one medium Electromagnetic wave- a wave consisting of changing electric and magnetic fields, that is emitted by vibrating electric charges and can travel through a vacuum

3. Science 8 Module J Unit 1 Lesson 2 Properties of Waves

4. Wave- a disturbance that transfers energy from one place to another Amplitude- measure of how far the particles in the medium move away from the normal rest position Wavelength- the distance from any point on a wave to an identical point on the next wave Wave Period- the time required for corresponding points on consecutive waves to pass a given point. Frequency- the number waves, in a given cycle Hertz- a unit of frequency equal to one cycle per second Wave Speed- the speed at which a wave travels, speed depends on the medium Wave speed = frequency x wavelength

6. Student Access Module J Unit 1 Lesson 2 Virtual Lab

7. Unit 1 TEST Review
Medium- the material through which a wave travels Longitudinal Waves- partials move parallel to the wave (sound) Mechanical Wave- can travel though more than one medium Wavelength- the distance from any point on a wave to an identical point on the next wave Wave speed = frequency x wavelength Frequency- the number waves, in a given cycle

8. As a wave progresses the particles move in one direction, then the opposite and returns to its original position.

9. *A phone is placed in a vacuum sealed container, what will you observe when the phone rings?
Sound waves are mechanical waves, mechanical waves CANNOT travel through empty space.
Light waves are electromagnetic, EM waves CAN travel through empty space.
Thus, the sound waves would NOT be heard by an observer, but the light waves would reach the observer.

10. Science 8 Module J Unit 2 Lesson 1 Sound Waves and Hearing

11. Sound Wave- a longitudinal wave that is caused by vibrations and travels through a medium Longitudinal Wave- particles of a medium vibrate in the same direction that the wave travels. (also called compression waves, made of compressions and refractions) Refaction- is the part where particles spread apart Pitch- how high or low you think a sound is, depends on the frequency and wavelength of a sound Loudness- a measure of how well a sound can be heard Decibel- the most common unit used to express loudness Doppler Effect- a change in the observed frequency of a wave when the sound source, the observer, or both are moving.

12. Decibel Levels of Common Sounds
The softest sound you can hear 20
Whisper 60
Normal conversation 80
Lawn mower, vacuum cleaner, truck traffic
115
Sand blaster, Loud rock concert, Car Horn
120
Threshold of pain

13. Science 8 Module J Unit 2 Lesson 2 Interactions of Sound Waves

14. Echo- a reflected sound wave Interference- happens when two or more waves overlap and combine to form one wave Resonance- happens when a sound wave matches the natural frequency of an object and causes the object to vibrate. * Ultrasound waves do not transmit easily through bone. How do ultrasound wave create this picture?

15. Science 8 Module J Unit 2 Lesson 3 Sound Technology

16. Echolocation- the use of echoes, reflected sound waves to find objects Ultrasound- high frequency sound waves that humans cannot hear
Sonar- technology that uses echolocation to navigate and locate objects

17. Daily Demo: What a Difference
I am happy to join with you today in what will go down in history as the greatest demonstration for freedom in the history of our nation. Five score years ago, a great American, in whose symbolic shadow we stand today, signed the Emancipation Proclamation. This momentous decree came as a great beacon light of hope to millions of Negro slaves who had been seared in the flames of withering injustice. It came as a joyous daybreak to end the long night of their captivity. But one hundred years later, the Negro still is not free. One hundred years later, the life of the Negro is still sadly crippled by the manacles of segregation and the chains of discrimination. One hundred years later, the Negro lives on a lonely island of poverty in the midst of a vast ocean of material prosperity. One hundred years later, the Negro is still languished in the corners of American society and finds himself an exile in his own land. And so we've come here today to dramatize a shameful condition.
Daily Demo: What a Difference

18. How do CDs Work?

19. Module J Unit 2 Test Review

20. Frequency- the number of sound waves in a give cycle Hertz- measurement used for decibels of sound Rarefactions- section of wave where particles spread apart Resonance- Ex. The body of a violin vibrating from the sound of a plucked string Echolocation- ultrasonic waves, bats use How does the inner ear work? The inner ear converts sound waves to electrical signals How does temperature affect the way sound travels? The warmer the temperature, the further sound will travel How does material affect the speed of sound? Sound travels faster in water than in air

21. How does a guitar string vibrating at a greater height affect the volume? The greater the vibration height, the greater the volume
How might you make a soundproof booth? I would use thick carpet, heavy curtains, and foam padding
What part of the telephone changes sound waves into electrical waves?
The microphone
How are CDs different from digital files? A CD stores sound as pits on the CD’s surface, a digital file stores sound as computer code

22. What does destructive interference of two transverse waves look like?
How could you describe the wavelength of a high pitched sound? The wave length of a high pitched sound would be short.
How could you describe the decibels of a very loud sound? The decibels of a very loud sound would be high.

23. Electromagnetic spectrum:
Radio
Microwave
Far Infrared
Near Infrared
Visible Light
Ultraviolet
X-Rays
Gamma-Rays

24. Science 8 Module J Unit 3 Lesson 1 The Electromagnetic Spectrum

25. Electromagnetic Radiation- the transfer of energy as EM waves (electromagnetic) Electromagnetic spectrum- the full range of wavelength of EM waves

26. Infrared- (IR light) has slighter longer wave lengths than red light (infra- below)
Ultraviolet- (UV light)has slightly shorter wave lengths than violet light (ultra- beyond)

27. Science 8 Module J Unit 3 Lesson 2 The Interactions of Light

28. Transparent- matter that transmits light (air, water, clear glass) Translucent- matter that transmits some light, but not all, (frosted glass, waxed paper) Opaque- matter that does not allow any light to pass through, (wood, brick, metal) Absorption- the transfer of light energy to matter Reflection- the bouncing of light off a surface Refraction- the change in direction when light passes from one medium to another at an angle (straw in a glass of water) Scattering- light is sent in many directions as it passes through a medium (dust particles, fog)

29. RED
ORANGE
YELLOW
GREEN
BLUE
VIOLET

30. Science 8 Module J Unit 3 Lesson 3 Mirrors and Lenses

31. Virtual Image- an image that appears to come from a place that light does not actually come from Concave- curves inward Converge- to come together Real Image- formed where light from an object converges Convex- curves outward Diverge- spread apart Lens- a optical tool that refracts light

32. Size of image compared to object
Virtual or Real?
Orientation of Image
Size of image compared to object
Optical Devise
Example
Virtual
Right side up
Larger
Convex lens
Magnifying glass
Concave Lens
Magnifying mirror
Smaller
Glasses for nearsighted
Convex
Security mirrors
Real
Upside down
Concave
Headlights
smaller
Camera

33. Science 8 Module J Unit 3 Lesson 4 Light Waves and Sight

34. Cornea- the transparent membrane that forms the front of the eye
Cornea- the transparent membrane that forms the front of the eye. Light waves enter the eye through the cornea Retina- the light sensitive tissues that lines the inside of the eye receive images
Retina
Cornea
Pupil
Lens
Optic Nerve

35. Rod Cells Cone Cells Both
Detect light
Are cells in the retina
Detect color and brighter light
Detect dim light

38. Science 8 Module J Unit 3 Lesson 5 Light Technology

39. Incandescent Light- visible light is produced from a very hot material inside the bulb. Only 8% of the energy giving off is in the form of visible light Fluorescent Light- visible light is produced by the energizing if gases coating the inside of the bulb. About 80% of the energy given off is in the form of visible light LEDs- contain solid materials that emit light when energized by an electrical current. Almost 100% of the energy given off is in the form of visible light Laser- produces a very intense light of a very small range of wavelengths. Optic Fiber- a thin transparent glass thread that transmits light over long distances

40. Unit Review
Translucent- ex. Foggy morning Reflective images- vary in many ways from the actual object Cone Cells- distinguishes different colors Converging Lenses- convex lenses Electromagnetic Radiation- the transfer of energy as electromagnetic waves LED light- type of light technology that emits light by energizing solid particles with an electrical current If two people see the same object in a mirror, where does the image seem to come from? The image appears to be behind the mirror

41. What will happen when parallel beams of light hit a converging mirror
What will happen when parallel beams of light hit a converging mirror? The light comes together to a single focal point. What happens to light images when they hit the retina? The images are sent to the brain. How might a surgeon correct nearsightedness? Flatten the cornea How might corrective lenses correct farsightedness? By using a converging lens How are glasses a type of light technology? Glasses help us control light

42. How are the frequency and wavelength of electromagnetic waves related
How are the frequency and wavelength of electromagnetic waves related? The higher the frequency, the shorter the wavelength The lower the frequency, the longer the wavelength If you have a red paper, what color will it look when you look through a red glass? Why? red, because only red light goes through the red glass What color would it appear if you looked through a blue glass? Why? Black, because only blue goes through the blue glass Light through a prism: