1. Physics Unit 5 Waves – Light & Sound

2. Wave
A rhythmic disturbance that transfers energy through matter and/or a vacuum
Material a wave travels through is called the medium
2 types of waves:
1. Transverse
2. Compressional (Longitudinal)

3. Transverse
Matter in the wave moves at right angles to the direction of the wave front
Wavelength (λ)
Crest
amplitude
mid line (resting position)
Trough
Examples: gamma radiation, x-ray, UV, visible light, infrared, microwave, radio, TV, water

4. Compressional (Longitudinal)
Matter moves in the same direction as (along with) the wave front
compression λ
rarefaction
Example: sound

5. Transverse & Compressional
Amplitude (A)
-determined by amount of energy
Wavelength (λ)
-determined by the wave frequency
Frequency (f)
-number of waves per second
-measured in hertz (Hz)

6. Transverse & Compressional
Velocity (v)
v = λf
-varies based on temperature, what it is traveling thru
-stays the same in a given medium
velocity of light (all transverse waves)
- 300,000,000 m/s
velocity of sound (longitudinal waves)
-330 m/s

7. Frequency Comparisons
Transverse
Longitudinal
High frequency
High frequency
-High pitch
-purple light
Low frequency
low frequency
-red light
-low pitch

8. Amplitude Comparisons
Transverse
Longitudinal
High amplitude
High amplitude
-loud
-bright light
Low amplitude
low amplitude
-dim light
-quiet

9. Transverse vs. Longitudinal

10. Check up Which has a longer λ? -A Which has higher frequency? -B
Which has higher amplitude?
-both same