1. PHYSICS Mr. BALDWIN WAVES 15-Jan-14
AIM: How can we describe a wave?
DO NOW
What are some things you know about a wave?
Light and heat energy comes to us from the Sun. How does it get here?
What is the name and call number of your favorite radio station?
Do you know what the call number represents?
HOME WORK: WkSh 20.1: Waves

2. Wave Motion: Wave characteristics
A wave is a periodic disturbance that transfers energy from one point to another
ex. light, sound, (electromagnetic {E-M} waves)
Water waves, sound waves, and light waves are very different from one another in various ways, but all have in common some basic properties:
Wavelength
Frequency
Period
Amplitude
Wave speed

3. Wave characteristics Amplitude, A Frequency f and period T
Wavelength, l

4. Wave Properties
Wavelength l is the distance between successive points on a wave. Ex. distance between adjacent crests or troughs.
Meters (m)
The frequency f of waves is the number of waves passing a particular point per second.
Hertz (Hz)
The period T is the time needed for a one complete wave to pass a given point.
Seconds (s)
The amplitude A of a wave is the maximum displacement on either side of its normal position of the wave.

5. CHECK
Below is a snap shot of a wave travelling for 1 sec. About how many waves do you see? What is the period and frequency of the wave?

6. Wave Property Relations
The frequency is inversely proportional to the period
Hz = 1/s
The wave speed is equal to the product between the frequency & wavelength
m/s
Speed of light (E-M)
c = 3.0 x 108 m/s
Range of visible light
l: nm.

7. CHECK
What is a nm?
10 -9 m
What are the call letters and numbers of your favorite radio station?
107.5WBLS
Do you know what the numbers represent?
frequency (in MHz)
What is a MHz?
10 6 Hz
What is the wavelength of such a wave?