Physics - Chapter 3 (waves)

the highest point on a wave above the equilibrium

crest

the lowest point on a wave below the equilibrium

trough

the distance between successive crests of a wave

wavelength

the max or min displacement from the equilibrium

amplitude

transfer energy without the transfer of matter

waves

waves travel in a direction perpendicular to the direction of vibration

transverse

waves travel in a direction parallel to the direction of vibration

longitudinal

v = f x λ

wave speed

time taken to complete one oscillation of a wave

time period

each wavefront represents a single wave

wave front

short wavelength

wavefront (closer)

longer wavelength

wavefront (far apart)

when a wave hits a boundary between two different media and doesn't pass through

reflection

angle of incidence = angle of reflection

law of reflection

when a waves passes a boundary (between two different media) and undergoes a change in direction

refraction

when the wave slows down and wavelength decreases wave bends towards the normal

refraction towards the normal

when the wave speeds up and the wave length increases

refraction away from the normal

when a wave passes through a narrow gap and spreads out

diffraction

the line at the right angle to the boundary is called normal

normal

the angle between the incident ray and the normal

angle of incidence

angle between reflected ray and the normal

angle of reflection

1) the same size as the object
2) the distance behind the mirror as the object infront of it
3) directly in line with the object

characteristics of reflection in plane mirror

an image that is formed when the light rays from an object do not meet but appear to meet behind the screen eg: mirror (virtual images are upright)

virtual image

an image that is formed when the light rays from an object converge (meet eachother) and can be projected on a screen

real image

frequency

during refraction what does not change

the ratio of speeds in two different regions

refractive index (n)

if light travels from less dense to more dense r < i and vice versa

snells law

n = sin i divided by sin r

snells law formula

angle of incidence when angle of refraction is 90

critical angle

occurs when i > c and the incident material is denser (eg: glass to air)

total internal reflection

telescope, periscope, binoculars

examples of things that use total internal reflection

sinc c = 1/n

sin c formula

the line that passes through the center of a lens

principal axis

the point at which the rays of lights travelling converge

principal focus/focal length

the distance between the center of the lens and the principal focus

focal length

has a single frequency

monochromatic