chapter 14&15 Flashcards
Wave
a periodic disturbance a periodic disturbance in a solid, liquid, or gas as energy is transmitted through a medium.
Mechanical Waves
waves that require a medium to propagate.
EM waves
a wave that consists oscillating electric and magnetic fields, which radiate outward at the speed of light.
Medium
a physical environment in which phenomena occur
Sound waves
are longitudinal waves & spread out in spherical wavefronts.
two types of waves
traverse & longitudinal
Longitudinal Wave
a wave in which the particles of the medium vibrate parallel to the direction of wave motion. picture p. 464 & 461
Traverse Wave
a wave in which the particles of the medium move perpendicular to the direction the wave is traveling. pict. p 460
Surface Waves
- Occur at the boundary between two different media.
- Particles move in both longitudinal and traverse directions.
Crest
the highest point of a wave.
Trough
the lowest point of wave.
Amplitude
from zero to the max value.
wavelength
lambda = v_wave* T = v_wave/f.
reflection
the reflection of a wave from an object.
interference
the combination of two or more waves of the ?same frequency that results in a single wave
wave superposition
unlike particles waves can occupy the same space at the same time
Standing Wave
the result of destructive & constructive interference. The reflected wave travels in the opposite direction, constructive interference producing crests and troughs, and destructive interference producing nodes. there are actually waves traveling in both directions, the VISUAL makes it seem like it’s standing still. see page 478.
pitch
the measure of how high or low the sound is perceived to be. depends on the frequency of the wave.
resonance
the phenomenon that occurs when two objects naturally vibrate at the same frequency.
Sonar
Sound Navigation & Ranging.
photon’s energy
directly proportional to the frequency. a “blue light” photon has more energy than a “red light” photon
intensity
the rate at which energy flows through a given area of space.
RADAr
radio detection and landing.
Light Ray
a line in space the matches the direction of the flow of radian energy
Diffuse Reflection
Rough surfaces reflect light rays in many directions
non-defuse reflection
Smooth Surface reflect light in one direction
Law of Reflection
angle of incidence is equal to the angle of reflection.
Virtual Image
am image that forms at a coalition that which light rays appear to come but do not actually come.
Black Color
actually an absence of colors.
Refraction
- the bending of a wavefront as the wavefront passes between two substances (media) in which the speed of the waves differs. ie. light bends when it passes from one medium into another.
- The angle depends on the speed of light in the media.
Refraction from faster medium to slower medium
when light from air to glass(slower light speed), it’s path is bent toward the normal.
refraction from Faster medium to slower medium
when light passes from glass to air, its path is bent away from the normal.
Total Inertial Reflection
the complete reflection that takes place within a substance when the angle of incidence of light striking the surface boundary is less than the critical angle.
Lens
a transparent object that refracts light waves such that they converse or diverge to create an image.
Prism
a system that consists of two or more plane surfaces of a transparent solid at an angle with each other.
Dispersion
- the process of separating a wave of different frequencies into its individual component waves.
- In fluid dynamics, dispersion of water waves generally refers to frequency dispersion, which means that waves of different wavelengths travel at different phase speeds.
Intensity
Power/ boundary surface = P/(4Pir^2).
