1. Lesson P1 – Properties of Waves
Unit 3 - Physics
Lesson P1 –
Properties of Waves

3. Features of a Wave
A wave is a movement that transfers energy through matter.
Sound waves disturb the air and transfer energy through it.
Ocean waves disturb the water and transfer energy through it.
Energy is the capacity to apply a force (a push or a pull on an object) over a distance.

4. Features of a Wave

5. Two Types of Waves Water waves are an example of transverse waves.
Matter in the medium (water) moves up and down.
The wave and the energy move perpendicular (at 90°) to the matter.

6. Two Types of Waves
Sound waves are an example of compression (or longitudinal) waves.
Matter in the medium (air) moves in the same direction as the wave and the energy.

8. Frequency
Frequency is the number of repetitive motions, or oscillations, that occur in a given cycle.
As the wavelength decreases, the frequency increases (there will be more, shorter waves).
As the wavelength increases, the frequency decreases (there will be fewer, longer waves).

9. Calculating Frequency
We measure frequency in hertz (Hz):
# of cycles ÷ seconds

10. Calculating Frequency
Calculate the frequency of each pendulum below, and then rank them from lowest to highest frequency.
Pendulum
Number of Swings
Time to Complete all Swings
Frequency
Rank A 32
8 s B 72
9 s C
240
1 min 20 s