1. What are waves? A disturbance that travels through matter or space
They transfer energy from place to place but do not transfer matter.
A wave transfers energy without transferring matter from one place to another.
EX: In water, energy in waves move but the water molecules move only a short distance.
Vibrating objects create waves

2. What do waves travel through
Medium – the material through which waves travel.
They travel through types of Matter – solids, liquids or gas Or Space
The speed of the wave depends on the medium they travel through

3. What are the types of waves
Mechanical – only travel through matter
Can be transverse or longitudinal
In transverse – the particles move perpendicular to the energy of the wave
- Water waves
In longitudinal – the particles move parallel
- sound waves
Electromagnetic – travel through matter and space – Don’t need a medium to travel through
- light waves

4. How do we describe waves?
Amplitude - measure of how far particles in the medium are from their normal rest position.
(the maximum displacement from resting position)
As a wave passes, particles vibrate up and down or back and forth in the medium
Crests = highest points
Troughs = lowest point

5. What is this wave’s amplitude?

6. Amplitude
Which has a larger amplitude A or B? Why?

7. 2 Wavelength
distance over which the wave’s shape repeats
Distance from any point on a wave to the same point later on the wave
Ex crest to crest, or trough to trough.

8. What is this wave’s wavelength?

9. 3. Frequency – number of crests (or troughs) that pass per unit of time
Wave period – is the amount of time for one wavelength to pass a given point
Ex/ time between 2 crests
Frequency gives a unit of time
Ex/ # of crests per second
Measured in Hertz = 1 Hz = 1 wavelength per second

10. If 1 second passes, what is the frequency of
Wave A?
Wave B?

11. What affects the energy of a wave?
Amplitude – high amplitude = high energy
Frequency – (in EM waves),
high frequency = high energy
X-rays = high
radio waves = low
Waves lose energy due to friction and wave spreading – movement in all directions.

12. You just came home from a day at the beach
You just came home from a day at the beach. You swam in the ocean and stretched out in the sunlight. Your friend brought a radio so you could listen to music. When you arrived home, you heated some pizza in the microwave oven. As you waited for it to cook, you turned on the TV, and then the phone rang.
List examples of the waves in the story AND classify as mechanical or electromagnetic

13. Longitudinal Wave Compressional Wave wave particles vibrate back
and forth along the path that
the wave travels.
Compressional Wave

14. Compressions
The close together part of the wave
Rarefactions
The spread-out parts of a wave

15. Transverse waves
wave particles vibrate
in an up-and-down motion.

16. Transverse waves Crests Highest part of a wave Troughs
The low points of the wave

17. Waves transfer energy without transferring matter.
Frequency= waves/time

18. Wave Velocity - is the speed with which a wave crest passes by a particular point in space
It is measured in meters/second.
Wave Velocity = Frequency  Wavelength

19. Speed of Sound air (0 C) 331 water (25 C) 1493 sea water 1533
Medium velocity m/sec
air (20 C)
air (0 C)
water (25 C)
sea water
diamond
iron
copper
glass