18 The expressions for the amplitudes of reflected and trans-
mitted waves depend on the unitless ratiov 2 /v 1 (or, more generally,
on the ratio of the impedances). Call this ratioα. (a) Show that
changingαto 1/α(e.g., by interchanging the roles of the two media)
has an effect on the reflected amplitude that can be expressed in a
simple way, and discuss what this means in terms of inversion and
energy. (b) Find the two values ofαfor which|R|= 1/2.Key to symbols:
√easy typical challenging difficult very difficult
An answer check is available at http://www.lightandmatter.com.396 Chapter 6 Waves