http://www.ck12.org Chapter 17. Light
MEDIA
Click image to the left for more content.MEDIA
Click image to the left for more content.- Waves are characterized by their ability to constructively and destructivelyinterfere. Light waves which
interfere with themselves after interaction with a small aperture or target are said todiffract. - Light creates interference patterns when passing through holes (“slits”) in an obstruction such as paper or the
surface of a CD, or when passing through a thin film such as soap. - Light of different frequencies traverse materials at slightly different speeds. Thus, they refract at slightly
different angles when going through a material. This explains why white light is separated into its individual
frequencies forming a rainbow. This fact combined with refraction and the perspective of the viewer combines
to explain how rainbows are formed.
MEDIA
Click image to the left for more content.Key Equations
λf=cThe product of the wavelengthλof the light (in meters) and the frequencyfof the light (inHz, or 1/sec) is always
equal to a constant, namely the speed of lightc= 300 , 000 ,000 m/s.
n=
c
uThe index of refraction,n, is the ratio of its speed(c)in a vacuum to the slower speed(u)it travels in a material.n
can depend slightly on wavelength.