1. SSA Review 7 –
Energy and Waves

3. What is electromagnetic radiation?
*the energy that is moved by E.M. waves
*it travels through empty space, air, and water and moves at the speed of light (186,000/mps)

4. 3 – What is the electromagnetic spectrum?
*the range of energy composing E.M. waves
*every wavelength travels at the same speed

5. A) Radio waves - has the longest wavelength and lowest energy
*Examples of how this energy is used:
Broadcasting radio and TV programming
Used to pick up transmissions from outer space

7. B) Microwaves *Shorter than radio waves, but has more energy
*Examples of how this energy is used:
Cooks food faster than conventional ovens
Radar to detect speed and movement
Cellular signal transmissions (cell phones, text messages, photos, etc.), able to penetrate through clouds and haze in the atmosphere

9. C) Infrared rays *waves that are felt as heat
*Examples of how this energy is used:
Night vision goggles used to detect people in the dark
Animals use this to detect warm-blooded prey
Remote controls use this to change channels/settings
Used to detect stars too far away to be seen

11. D) Visible light
*The only energy that can be seen by our eyes *the smallest part of the E.M. spectrum
*Examples of how this energy is used:
- Used by light bulbs to provide light
- Used to view objects in space through telescopes

13. E) Ultraviolet (UV) rays
*waves shorter than, but more energy than visible light
*most of these waves are blocked by the ozone layer
*Examples of how this energy is used:
- Our bodies need it to produce Vitamin D (good for skin) *too much can cause skin damage
Used in fluorescent lighting
Used in dental and medical practices to kill bacteria

15. F) X-rays
*Small, but very high energy waves that can penetrate most matter
*Examples of how this energy is used:
Used to produce images of bones, teeth, etc.
Used in scanners to detect a variety of hidden objects
Used in equipment that can detect cracks and other deficiencies in objects or structures
Too much exposure can cause cancer to humans

17. G) Gamma rays
*has the shortest wavelength, but the most energy the most penetrable of all the E.M. waves produced from nuclear explosions & radioactive atoms
*Examples of how this energy is used:
Used medically to kill cancerous cells (too much can cause cancer, though)
Used to sterilize medical equipment

19. Properties of waves
*Crest – highest point of a wave
*Trough – lowest point of a wave

20. How do the different waves compare?
*Each part of the wave has different wavelengths (the distance between one crest to another)

21. *every wavelength travels at the same speed
*Radio waves are the longest, Gamma rays the shortest
*every wavelength travels at the same speed

22. *The shorter the wave, the faster the frequency
**Frequency – the rate the waves travel through a set distance
*The longer the wave, the slower the frequency
*The shorter the wave, the faster the frequency

23. **As the wavelength decreases, the energy of the wave increases.

25. Light Waves
1 – Light moves in a straight line unless it interacts with matter.

26. 2 – Light will bounce off a shiny object and change directions.
* This is reflection

27. 3 – Light can bend through an object that it passes through
*This is refraction.
Why? Light travels slower through another medium than it does through air

28. 4 – Light can be engulfed by an object and stop moving
4 – Light can be engulfed by an object and stop moving *This is absorption
**Darker colored objects absorb more light energy than other colors

29. 5 – Light passes through an object
*This is transmission

30. Light Waves

31. Sound Waves SOUND WAVES LIGHT WAVES Velocity in Air Form
Transmitting Medium
Relation of Transmitting Medium to Velocity
Sensations Produced
Variations in Sensations Produced
1,100 feet per second
Longitudinal
All substances
The denser the medium, the greater the speed
Hearing
Low frequency, low note
High frequency, high note
186,000 miles per second
Transverse
Empty space and all substances except opaque
The denser the medium, the slower the speed
Seeing
Low frequency, red color
High frequency, ultraviolet color

32. Sound Waves *Moves slower than light waves
Sound Waves
*Moves slower than light waves
*Speed up when moving through any medium (solid, liquid, or gas)
*Does not move through empty space