## College Physics (4th Edition)

(a) The wavelength inside the glass is $455~nm$ (b) The frequency of the light inside the glass is $4.34\times 10^{14}~Hz$
(a) We can find the wavelength $\lambda'$ inside the glass: $\lambda' = \frac{\lambda_0}{n}$ $\lambda' = \frac{692~nm}{1.52}$ $\lambda' = 455~nm$ The wavelength inside the glass is $455~nm$ (b) The frequency of a wave does not change when the wave moves from one medium into another medium. We can find the frequency of the light in air: $f = \frac{c}{\lambda_0}$ $f = \frac{3.0\times 10^8~m/s}{692\times 10^{-9}~m}$ $f = 4.34\times 10^{14}~Hz$ Since the frequency of the light does not change, the frequency of the light inside the glass is $4.34\times 10^{14}~Hz$.