Waves And Communication Flashcards
Two types of waves
Longitudinal
Transverse
Longitudinal waves
Particles vibrate back and forth
Parallel to the direction of movement of the wave
Transverse waves
Particles vibrate up and down
Perpendicular to the direction of movement of the wave
Wave Are produced by
Vibrations
Longitudinal wave examples
Sound waves
Ultrasound waves
Slinky spring waves
Transverse waves examples
Water waves
Slinky spring waves
Electromagnetic waves
Wavelength
Distance between two crests or troughs (waves)
Amplitude
Height of a wave which is measured from the midline
Lowest Frequency humans can hear
20 hz to 20 kHz
Frequency in ultrasound range
30 kHz
What do waves carry
Energy
Wave equation
Velocity (speed)= Frequency (hz) x landa (wavelength)
Key features of sound
Can travel through solid, liquid and gases but not a vacuum
Travels quick through solids and slow through gases
Travels at 330 meters per second through air
Factors that affect persons hearing
Birth defects
Age
Damage to ear drum
Prolonged exposure to noisy environment
Echos
Is a reflected sound wave
Speed of sound of a firework
Stopwatch starts when u see the light of the firework, stopwatch stops when the bang is heard from the firework
Ultrasound
20 khz
We can’t hear because higher then hearing range
What ultra sound is used for
Sonar (depth of water or locating fish)
Radar (locating aircraft)
Industry
Medicine (scanning unborn babies and organs)
Electromagnetic waves
Travel in a vacuum
Travel same speed as a vacuum
Transverse waves
Carry energy
Can be reflected
How microwaves heat chicken
Microwaves are absorbed by water molecules in the chicken. Caused them to vibrate faster causing more friction between the molecules
Electromagnetic spectrum
Radio
Microwave
Infrared
Visible
Ultraviolet
X Ray
Gamma ray
