Chapter 6 Flashcards
What is a wave?
An oscillation accompanied by a transfer of energy, without a transfer of mass
Transverse waves are…
waves in which the oscillations are perpendicular to the direction of travel
Example of transverse wave
Electromagnetic waves (radio, micro, infrared, light, ultraviolet, x-ray, gamma)
Longitudinal waves are…
waves in which the oscillations are parallel to the direction of travel
Example of longitudinal wave
Sound wave
Frequency of a wave
- number of waves passing a point per second
- measured in Hertz (Hz)
Period of a wave
Time for one oscillation
period = 1/frequency
Wave equation (speed, frequency and wavelength)
Speed = frequency x wavelength
Wave effects
Reflection
Refraction
Diffraction
Reflection
Waves are reflected from a surface at the same angle they strike it
Diffraction is only significant if…
The gap is the same size (or similar) to the wavelength
Sound waves are caused by….
vibrations
Characteristics of sound waves
- Longitudinal
- need a medium to travel through
- Can travel through solids, liquids and gases
- Sound waves can be reflected, refracted and diffracted
Speed of sound
330m/s in air
What does the speed of sound depend on?
- the medium (travels fastest through more dense materials)
- temperature of the medium (moves faster through warm material)
What is a wavefront
The PEAK of a transverse wave or the COMPRESSION of a longitudinal wave
What is refraction
When a wave changes speed due to a change in medium
What is amplitude
Maximum disturbance from rest position when a wave passes
Why cant sound waves travel in a vacuum
They need particles to compress
What is ultrasound
Sounds above the human range of hearing
