1. Essential question: What are waves?
Unit 2 -Waves
Essential question: What are waves?

2. Recall Matter: Anything that has mass and takes up space.
2. Liquid
Matter: Anything that has mass and takes up space.
States of Matter:
1. Solid
3. Gas
Click on link below to watch video:

3. Recall Force: is a push or a pull
When a force happens it can create a vibration.
Vibration: a repeated back-and-forth or up-and- down motion.

4. What are waves?
Waves are created from a force.
They carry energy through empty space or through a medium WITHOUT transporting matter.
A medium is a material which waves can travel.
Can be: a solid, a liquid, or a gas
When traveling through a medium, the particles in the medium are not carried with it.
When there is not a medium only one type of wave can travel through empty space.

5. Demonstration: Watch the following 2 videos
movement of matter
wave movement demo

6. Types of Waves There are 2 categories that waves can be divided into:
1. Mechanical:
must have a medium
Can also be separated into how the particles vibrate. Mechanical waves can move as a compressional wave or a transverse wave.
2. Electromagnetic:
uses a medium, but CAN travel with out a medium in empty space
These waves will only travel as a transverse wave

7. Electromagnetic Waves
Mechanical Waves
Electromagnetic Waves
Must have a Medium
Can travel WITHOUT medium
Compressional
Transverse
Transverse

8. Movement of Waves Compressional: (longitudinal)
Move by pushing the particles together and then pulling apart
Where the particles are pushed together; the area is called a compression
Where the particles are pulled apart; the area is called a rarefaction
Transverse:
Move by making the particles go up and down or back and forth
The highest point of a transverse wave is called a crest
The lowest point of a transverse wave is called a trough
Draw the waves into your notes!!!

9. Characteristics of Transverse Waves
Transverse waves only – we will not be studying the same characteristics for compressional
Wavelength (λ): a measurement of the distance from one crest to the very next crest.
Amplitude: a measurement of the distance between a line through the middle of a wave and a crest or trough
The taller the wave the higher the amplitude
Frequency (ƒ): a measurement of how many waves pass a point in a certain amount of time
The higher the frequency the closer the waves are together

10. Amplitude changes – the taller the more energy
Frequency changes – the closer the waves are the more energy
Draw waves into your notes that are labeled correctly and show low and high amplitude and low and high frequency!!!

11. Characteristics of Transverse Waves
Speed: Recall v=d/t
the measurement of the distance a wave travels in a certain amount of time.
Speed depends on type of wave and the type of medium it is traveling through
If a wave is traveling through one type of matter and then moves to another; the speed will change
Frequencies will travel though empty space at the same speed.