Lesson 3 (Part 1) Flashcards
What are 4 examples of sound properties?
- Frequency
- Period
- Wavelength
- Propagation speed
What are 2 forms of waves?
- Mechanical
2. Electromagnetic
Mechanical wave (2)
- Needs a medium
2. Requires a physical interaction
Electromagnetic waves
Work in a medium or a vacuum
Waves
Transfer energy from one location to another
- cyclical
What are 2 forms of mechanical waves?
- Longitudinal waves
2. Transverse waves
What is an example of a longitudinal wave?
Sound
Which direction do particles vibrate in a longitudinal wave?
Back and forth
- parallel to the direction of travel
What direction do particles move in a transverse wave?
Up and down
- perpendicular to the direction of travel
What is an example of a mechanical wave?
Ultrasound
Compressional
When areas are closer together creating high pressure and a high density
Rarefaction
Areas that are farther apart creating low pressure and low density
What are 3 examples of acoustic variables?
- Pressure
- Density
- Particle motion/vibration
Where on the wavelength is there high density?
Crest
Where on the wavelength is there low density?
Trough
Where on the wavelength is the baseline?
Neutral
- middle
Density
Concentration of matter
- high and low
Particle motion/vibration
Oscillation
What is the formula for pressure?
P = F/A
- P = pressure
- F = force
- A = area
What is the unit for pressure?
N/m^2
- pascal (Pa)
What is the formula for density?
D = M/V
- D = density
- M = mass
- V = volume
What is the unit for density?
Kg/m^3
Cycle
Is one complete variation in pressure/density
What are the repetitive loops called?
Sinusoidal waveform
Frequency
Is a measure of how often something happens over time
What is another way to write Hz?
1/s
What is another way to write KHz?
1/ms
What is another way to write MHz?
1/us
Infrasound
Is a sound of a frequency too low for human hearing
Ultrasound
Is a sound of a frequency too hight for human hearing
