PHU 4 Flashcards
transverse wave
The direction in which the wave travels is perpendicular to the direction of the disturbance.
longitudinal wave
A wave in which the vibration of the medium is parallel to the direction the wave travels
wave
a vibration that causes a transfer of energy from one place to another.
medium
Material through which a wave travels (ground, air). when a wave travels through a medium it does not go anywhere it is just temporarily displaced.
mechanical wave
a type of wave that involves moving parts or pieces. the medium is physically displaces temporarily as a the wave travels through.
lowest to highest frequency
radio, microwave, infrared, visible, ultraviolet, x-ray, gamma
what can cause cancer
UV, Xray, Gamma
reflection
when a wave reaches a boundary between two media and some of the energy returns back to the first medium.
specular reflection
a reflection produced by a smooth surface in which parallel light rays are reflected in parallel (water, polished silver, mirror)
diffuse reflection
Reflection that occurs when parallel rays of light hit a rough surface and all reflect at different angles (shirt, paper)
Reverberation
reflections in a smaller area (sound in a classroom)
echo
reflects off a surface that is far away (building) delayed
refraction
when a wave changes directions as it passes from one medium to another. occurs from change in wave speed. (ex- heat shimmer)
Atmosphere Refraction
sunlight refracts as it passes through the atmosphere. as light enters the atmosphere it slows down.
prism
A piece of glass that seperates white light into colors of the spectrum.
diffraction
when a wave changes direction as it passes around the edges of a gap or barrier (water, sound, light)
interference
when two or more waves occupy the same space at the same time, they add together to make a bigger wave or they cancel to make a smaller wave.
superposition
when two or more waves occupy the same space at the same time
constructive interference
The interference that occurs when two waves combine to make a wave with a larger amplitude
destructive interference
The interference that occurs when two waves combine to make a wave with a smaller amplitude
destructive examples
- noise cancelling headphones
-corners of a tuning fork
resonance
A phenomenon that occurs when two objects naturally vibrate at the same frequency.
double slit experiment
demonstrates that light has properties of both waves and matter
magnetic field
region of space where a magnetic force can be felt
Relationship between magnetic and electric
An electric field creates a magnetic field (vise versa)
Relationship between magnetic and electric
An electric field creates a magnetic field (vice versa)
how do we break down light with a spectrum
with a prism, double slit experiment (if we shine light through slits you will see light and dark spots on the wall because the light diffracts).
dark spots
nodal points where light from 2 slits interfere destructively.
bright spots
antipodal points where light from 2 slits interfere constructively.
Multiple slit grating
bright spots are spread out, 2 areas of destructive interference are larger
diffraction grating
a device made of thousands of closely spaced slits through which light is passed in order to produce a spectrum
wave equation
V=F*Lambda (wavelength)
are sound waves longitudinal or transverse
longitudinal
are sound waves mechanical or nonmechanical
mechanical
water wave
mechanical transverse
slinky wave
mechanical, transverse, longitudinal
sound wave
mechanical longitudinal
light wave
electromagnetic transverse
Mechanical wave
require a medium in order to transport their energy from one location to another.
electromagnetic waves
waves that are created as a result of vibrations between an electric field and a magnetic field.
longitudinal wave
a type of wave that travels in the direction of the medium
Transverse wave
a wave vibrating at right angles to the direction of its propagation
