1. 8.P.3A.1-2 Notes

2. Waves
Waves are created when a source of energy (force) causes a vibration.
Vibration: a repeated back and forth or up and down motion.

3. How Waves Travel There are two ways a wave can travel:
Through a medium.
Medium: material through which waves can travel; a solid, liquid, or gas
The particles of the medium do not move along with the wave they vibrate.
ALL waves can travel through a medium.
Through empty space.
ONLY electromagnetic waves.

4. Types of Waves There are TWO types of waves Electormagnetic Mechanical
Waves that can travel through matter or empty space where matter is not present.
They make up the Electromagnetic Spectrum
Mechanical
Require particles of the medium to vibrate in order for energy to be transferred
There are 2 types: Compressional and Transverse

5. How Mechanical Waves Move
Compressional Waves:
The particles in the medium vibrate by pushing together and moving apart parallel to the direction in which the wave travels.
The place where it is pushed together is a COMPRESSION.
The place it is spread apart is a RAREFACTION.

6. How Mechanical Waves Move
Transverse Waves:
The particles in the medium vibrate by moving back and forth and perpendicular to the direction the wave travels.
The highest point of the wave is called a CREST.
The lowest point of the wave is called a TROUGH.

7. Frequency
A measure of how many waves pass a point in a certain amount of time

8. Amplitude
A measure of the distance between a line through the middle of a wave

9. Amplitude
The greater the forces that produces a wave, the greater the amplitude of the wave and the greater the energy the wave has.
Sounds with greater amplitude will be louder.
Light with greater amplitude will be brighter.

10. Wavelength
A measure of the distance from the crest on one wave to the crest on the very next wave.

11. Wavelength Wavelength is influenced by frequency.
Higher frequency causes shorter wavelengths
Less frequency causes longer wavelengths

12. Speed = Distance / Time Wave Speed = Wavelength * Frequency V = λ * f

13. Wave Speed
A measure of the distance a wave travels in an amount of time
Determined by the type of wave and the nature of the medium.
Waves change speed when they change mediums.