1. wave – a regularly repeating pulse
Wave Properties

2. Transverse Wave – particles of the medium move PERPENDICULAR to the wave’s direction of travel

3. Motion of particles in the medium
Transverse Wave – particles of the medium move PERPENDICULAR to the wave’s direction of travel v
crest
wavelength (λ) A
amplitude
Motion of particles in the medium
SLINKY WAVES [Ex: Light/EM waves]
Faster in SPARSE (not dense) mediums
trough

4. Longitudinal Wave – particles of the medium move PARALLEL to the wave’s direction of travel.

5. Faster in DENSE mediums
Longitudinal Wave – particles of the medium move PARALLEL to the wave’s direction of travel.
wavelength (λ) v
compression
SOUND WAVES
Faster in DENSE mediums
rarefaction
Motion of particles in the medium

6. Definitions PERIOD - time for one oscillation – [Unit: seconds]
FREQUENCY - number of oscillations per second [Unit: 1/seconds or Hertz (Hz)]
Equation

7. Wave Velocity Waves have a definite direction of travel.
Wave period (T) = TIME FOR A WAVE TO REPEAT
Wave frequency (f) = NUMBER OF WAVES PER SECOND
IMPORTANT: ONCE A WAVE IS PRODUCED ITS FREQUENCY CANNOT BE CHANGED!
Wavelength (λ)= DISTANCE FROM CREST TO CREST (OR COMPRESSION TO COMPRESSION)
Equation

8. Amplitude would increase
Examples
A wave with a frequency of 1.5 hertz is moving through a heavy spring where its wavelength is 2.0 meters.
What would probably happen to the amplitude of this wave after it moves into the lighter spring?
What wavelength would the wave have if it moved into a lighter spring where its speed was 6.0 meters per second?
What is the speed of this wave?
Amplitude would increase
v = 3.0 m/s
λ = 4.0 m

9. Practice
1. What is the speed of a water wave with a wavelength of 10 meters if it has a frequency of 0.15 Hz?
2. A man on a beach notices that four waves arrive on the shore every 20 seconds. What is the frequency of the waves?
3. A sound wave travels from air to metal. What happens to its speed as it makes this change?
4. Why is the sound from a speaker louder when you sit closer to it?

10. Answer Key 1. 1.5 m/s 2. 0.2 Hz 3. Oscillates faster
4. Wave has more energy/amplitude

11. Day 2

12. Wave Categories
Mechanical Waves (Example: Sound, Ocean waves (Ripples), Earthquakes, etc)
EM Waves (Example: Radio waves, microwaves, light waves, x rays, etc)

13. Wave Phase What is the direction of motion in the medium?

14. Wave Phase Two points are considered to be “in phase” if they are moving in the same direction at the same time.

15. Wave Phase The number of degrees “out of phase” depends on the difference in wavelength between the points.
0° = whole wave
90° = 1/4 wave
180° = 1/2 wave
A/D; B/E
A/B; B/C; D/E
A/C; C/D; E/F v A D B E F C