1. Science
Notes: Stnds 6, 7, & 8
Date
Standard 06: 8.PS4.1 Properties of Waves
Develop and use models to represent the basic properties of waves including frequency, amplitude, and speed.
Standard 07: 8.PS4.2 Mechanical and Electromagnetic Waves
Compare/contrast mechanical waves and electromagnetic waves based on refraction, reflection, transmission, absorption and their behavior through a vacuum and/or various media.
Standard 08: 8.PS4.3 Waves and Communication Systems
Evaluate the role that waves play in different communication systems.
I Can Statement
...I can explain wave properties, compare and contrast
mechanical and electromagnetic waves, and describe waves in
communication systems.

2. Link (12 sec): Water Ripples
Science
Notes: Standard 6
8.PS4.1
What are Waves?
Waves are pulses of energy transmitted from one point to another.
energy but not mass is transmitted until it dissipates.
some waves only move through mediums (solid, liquid, gas, etc.)
energy conversions-potential to kinetic to potential energy.
Link (12 sec): Water Ripples
Graphing Waves
Waves are graphed as periodic oscillations (sine pattern)
Sine Pattern

3. Science Notes: Standard 6 8.PS4.1 Wave Frequency
Frequency is the quantity of waves that pass a fixed point in a given direction during a specific amount of time.
for sound waves (music), frequency is the pitch, high or low
unit for frequency is the hertz (Hz) , where one hertz equals one wave passing a fixed point in one second. 
High Pitch
Sound Wave
Low Pitch
Sound Wave

4. Wave speed
the speed which a wave travels
calculated by multiplying the wavelength times the frequency

5. Crests and Troughs
crests are the high points and troughs are the low points.
Wavelength
is the distance from crest to crest (or trough to trough).
Amplitude
height of the wave measured from the equilibrium line.
larger amplitude waves are louder, smaller amplitude is quieter.

6. Mechanical and Electromagnetic Waves
Science
Notes: Standard 7
8.PS4.2
Mechanical and Electromagnetic Waves
Mechanical Waves
Mechanical waves need a medium to be transmitted through.
They can only move through solids, liquids, gases, and plasma.
These waves travel more quickly through higher-density media.
So, waves travel faster through solids than liquids or gases.
Solid
Liquid
Gas

7. Mechanical and Electromagnetic Waves
These waves don’t need a medium to be transmitted through.
These waves can move through a vacuum (outer space).
Electromagnetic waves can also move through mediums
Examples: Light waves can move through glass windows (solid).
They can also move through air (gas) and through water (liquid).
Various Types of Electromagnetic Waves
1) Visible light waves
2) Infrared waves
3) Gamma ray waves
4) X-ray waves
5) Ultraviolet waves
6) Radio waves
7) Microwaves
Used with cell phones and radio stations

8. when a wave “bounces” back after impacting a surface. Example: An echo
Standard 07: 8.PS4.2 Mechanical and Electromagnetic Waves
Compare/contrast mechanical waves and electromagnetic waves based on refraction, reflection, transmission, absorption and their behavior through a vacuum and/or various media.
What is wave refraction?
when a wave bends as it moves from one medium to another.
Example: light moving from air to water
What is wave reflection?
when a wave “bounces” back after impacting a surface.
Example: An echo

9. Standard 07: 8.PS4.2 Mechanical and Electromagnetic Waves
Compare/contrast mechanical waves and electromagnetic waves based on refraction, reflection, transmission, absorption and their behavior through a vacuum and/or various media.
What is wave transmission?
movement of wave energy
Example: Recording music in a studio in Nashville
What is wave absorption?
absorption of wave energy
Example: Sound absorption material in recording studios

10. Standard 07: 8.PS4.2 Mechanical and Electromagnetic Waves
Compare/contrast mechanical waves and electromagnetic waves based on refraction, reflection, transmission, absorption and their behavior through a vacuum and/or various media.
What happens to waves in solids, liquid, gases?
Link (5:48): Sound-How Waves Are Transmitted
What happens to waves in a vacuum (outer space for example)?
Link (3:44): Can You Hear Sound in Space?

11. Watch Brainpop video about waves Link: Brainpop Website

12. Watch Brainpop video about sound Link: Brainpop Website