1. Waves Carry Energy Not Matter
A wave is a deformation(disturbance) that travels through a vacuum or medium (air, water, etc) that contains matter.
A wave transports ENERGY from one point to another NOT MATTER!
A wave in a medium needs matter to allow it to travel (sound needs air to travel. Outer space has no air, so no sound.)
A wave in a vacuum does not need a medium or matter to travel (outer space, x-rays, light waves).

2. Electromagnetic Spectrum
The organization of all electromagnetic waves according to their wave length and frequency
All electromagnetic waves carry energy.
Waves with higher frequencies and shorter wavelengths are able to carry larger quantities of energy. (high frequency = more energy)
High frequency waves can be dangerous for humans such as gamma rays which carry a lot of energy and can cause genetic mutations and cancer.

3. All Waves Have Frequency
Frequency: the number of cycles per unit of time.
Long Wave Length = low frequency
Short Wave Length= high frequency

4. All Waves Have Amplitude
Amplitude: the maximum height (or drop) a wave reaches from the rest position (equilibrium/no movement)
Ex – The amplitude of a water wave equals the distance between the crest of the wave and the undisturbed surface of the water.

5. All Waves Have Wavelength
Wavelength: the length of one complete cycle (this could be measured from crest to crest, from trough to trough, etc.).
Ex – The wavelength of a water wave equals the distance between 2 adjacent peaks.

6. All Waves Have a Crest and a Trough
Crest – the highest point (peak)
Trough – the lowest point

7. Diagram Examples Crest Long Wave Length = Low Frequency Wave Length
Amplitude
Trough
W L
Short Wave Length (WL) = High Frequency

8. The Electromagnetic Spectrum
There are many different kinds of electromagnetic waves (ex: radio waves, microwaves, light waves, etc.)
Each of these waves has a different wavelength
Gamma rays are very short, Radio waves are very long

9. Long Wavelength Short WAVELENGTH Low frequency High frequency
The Electromagnetic Spectrum
Long Wavelength Short WAVELENGTH Low frequency High frequency

10. The Electromagnetic Spectrum

11. Classification on Electromagnetic Spectrum
Types
Radio Waves
Infrared
Visible Light
UV Rays
X-Rays
Gamma Rays
Frequency
Energy
Tech
Applications
Interesting Facts

12. Types
Radio Waves
Frequency
Lowest
Energy
Tech
Applications
-Radio Cell phones
-TV MRI
-Microwaves
Interesting Facts
Antennas are used, which connect the signals

13. Types
Infrared
Frequency
Higher
Energy
Tech
Applications
-Night Vision Goggles
-Wireless Keyboard
-Satellites incubators
Interesting Facts
-Heat is emitted (given off)- “feels warm”
-Some animals use infrared to locate their prey

14. Types
Visible Light
Frequency
Energy
Tech
Applications
-Laser
-microscopes
-computer screens
Interesting Facts
-Only wave length we can see
-Red = longest wave length of visible light
-Violet = shortest wave length of visible light
- When visible light hits water vapour = rainbow

16. Rainbow An easy way to remember the order: R - Red O - Orange
Y Yellow
G Green
B Blue
I Indigo
V Violet

17. Types
UV Light
Frequency
Energy
Tech
Applications
-Sterilize Equipment
-Treatment for Jaundice
Interesting Facts
-Necessary for Vitamin D
-Causes Cancer
-Animals can sense them

18. Types
X-Rays
Frequency
Energy
Tech
Applications
-X-Rays
-Baggage and Body inspection at airport
Interesting Facts
-Too much can also cause cancer

19. Types
Gamma Rays
Frequency
Highest
Energy
Tech
Applications
- Preserving food
-Cancer treatment
Interesting Facts
- Given a + or – charge for cancer treatments
-Kills microbes in food

20. What is Light? Electromagnetic waves that are visible to the human eye
Travel in straight lines
Do not need a medium.

21. Light Waves Come in Different Sizes
All light together is white.
An object has colour because it absorbs all light except the color you see.
The light you see is reflected (bounced off)
Different colours of light have different wavelengths

22. When Light Hits a Surface it Can Be:
Reflected (bounce off) or Refracted (bends)

23. The Deviation of Light Waves
Light travels in a straight line as long as it does not encounter an obstacle;
If it hits an obstacle, a part of the energy is absorbed by the object. Some of the light rays bounce off the object (they are reflected);
If the object is translucent, like water or glass, some light rays travel through it but are diverted because of the change of density of the two medium (they are refracted (bent)).

24. Reflection
Occurs when light hits a medium and bounces back towards the direction it came from
Reflection is what allows us to see objects:
Lights reflects off an object and travels into the eyes → sight

25. Reflection Diagram Definitions:
Incident Ray: the ray that contacts the surface of an object
Reflected Ray: the ray that rebounds
Normal: a line perpendicular to the surface at the point of reflection
Angle of Incidence: the angle formed between the incident ray and the normal
Angle of Reflection: the angle formed by the reflected ray and the normal

26. Laws for Reflection of light rays:
The angle of incidence is always equal to the angle of reflection
The incident ray and the reflected ray are always in the same plane.

27. Reflection of Light Normal Angle of Reflection Angle of Incidence
Incident Ray
Angle of Reflection
Angle of Incidence
Reflected Ray

28. Reflection and Mirrors
When parallel light rays contact a surface such as a mirror, their reflections are parallel resulting in a true mirror image
A mirror with no curve, or that is flat is called a plane mirror
Reflections from plane mirrors have several characteristics:

29. The image appears to be behind the mirror
The distance between the object and the mirror and the reflected image and the mirror are equal in appearance
The image in the mirror is called a virtual image
A virtual image is not real and therefore cannot be captured on a mirror; it is made by lengthening the reflected rays.
The image seems to have the same shape, size and seems to be the same distance as the object, but the left-right orientation is inverted. (Selfie image)

30. Virtual Images Mirror Reflected Rays Reflected rays extended
Incident Rays
Object
Virtual Image

31. Uses of Plane Mirrors
The two principles that make plane mirrors useful are:
They change the trajectory (pathway) of light rays by reflection
This increase the observer’s field of vision
Uses: rear-view mirrors, microscopes, and telescopes

32. Plane Mirror: Virtual Image

33. How to draw the virtual object created with a plane mirror
Involves creating a symmetrical version of the object.
1. Draw straight lines from a few key points of the object to the surface of the mirror at right angles;
2. Continue these lines on the other side of mirror; these extensions should be equal distance as real object to mirror
4. The virtual object can be constructed.

34. Refraction
Refraction: the deviation of a light ray as it passes from one transparent medium to another
Occurs when the pathway of a light ray is changed
Most often occurs as light goes from air to water
Happens because the speed that light travels changes as the medium changes

35. Phenomenon whereby rays deviate from their trajectory when they pass from one translucent material into another translucent material that has a different density;
It bends or changes direction as it enters a new medium
Water, glass, plastic, diamonds and oil are examples of light-refracting material; (materials make light rays deviate from their course)
Light deviates from its path because it changes speed when it penetrates a different material;
When light ray moves out of water and into the air, its trajectory changes;
The brain still creates a virtual image from the extended rays perceived by the eye;
The deviation of light rays creates an image that is not where the real object is. .
Refraction
Pencil looks broken because brain misinterprets position

36. When Light is Refracted:
It bends or changes direction as it enters a new medium
ex: when a light ray goes from the air into glass

37. Predicting the trajectory of refracted light rays
From one material into another one with higher density, it moves towards the normal;
From one material into another one less dense, it moves away from the normal;

38. Lenses
Lenses are made of transparent materials (glass/plastic) and have at least one curved surface
The curve of a lenses allows it to refract light as it passes through

39. Lenses can Focus Light Because of Refraction
Light bends as it hits the surface of the lens
The point where the light rays meet is called the focal point
An image is formed on the retina, but it’s inverted (image inversion)

40. Two types of Lenses… Converging lenses: bring light rays together
Diverging lenses: cause light rays to spread out
Focal point
Focal point

41. Focal Point: Converging Lens
The focal point of a converging lens is the REAL POINT where the refracted rays ACTUALLY meet when the incident rays run parallel

42. Convergent lenses
Cause light rays traveling through to close in together;
They have at least one convex side (bulging outwards);
The rays all deviate toward the axis of the lens, the angle that divides the lens equally by its width;
The rays converge toward a precise point in the axis of the lens called the focal point of the lens;
The more pronounced (larger) the curve or the convergent lens is, the closer the focal point is to the lens and vice versa.
In our visual system, the lens of the eye acts as a convergent lens because its curved shape gives it the same structure as a convex lens
The lens of the eye is also flexible, so it can flatten or bulge out to adapt to the distance of the object to always converge the rays toward the retina.

43. Focal Point: Diverging Lens
The focal point of a diverging lens is the VIRTUAL point from which the refracted light rays APPEAR to emanate when the incident rays run parallel

44. Divergent lenses
Cause the light rays that traveling through to move apart from one another;
They have at least one side that is concave (bulging inward);
The rays are deviated away from the axis of the lens and when extension lines are drawn, they converge to the focal point of the divergent lens, the point where the original object is in front of the lens
The more pronounced the curve (larger the indent), the closer the focal point is to the lens, faster the rays deviate.

45. What is Sound?
Sound is a longitudinal mechanical wave made by the vibration of an object and transmitted to the object’s environment.
It cannot travel in a vacuum

46. Sound Waves
Anything that creates sound produces a longitudinal mechanical wave:
loudspeakers, musical instruments and thunder cause the air particles around them to vibrate.

47. Speed of Sound
The speed at which sound travels changes form one medium to another
Sound travels at 340 m/s in air
Sound travels faster in liquid or solid mediums- example: water = 1490 m/s, steel = 5200 m/s
Since sound waves produce deformations parallel to the direction in which they travel, they are considered longitudinal waves

48. The frequency (number of cycles per unit time) of sound is the pitch
High pitched sounds have a high frequency
Low pitched sounds have a low frequency

49. The Decibel Scale
The volume of a sound depends on its intensity, which is the amount of energy being transmitted
The greater the energy, the louder the sound
The decibel scale is a relative scale that represents the perception of the intensity of sound by the human ear

50. Variations on the decibel scale are measured in factors of 10
For each increase of 10 dB, a sound is 10 times louder (Example: a sound that is 20 dB is 100 times louder than a 0 dB sound)

51. Decibel Scale