Chapter 4.5, Problem 76E

To determine

a)

Show that the time required for the pulse to travel from $A$ to $Dis{t}_1=s/{\upsilon }_1$

To determine

b)

Show that the time required for the second pulse is

To determine

c)

Show that $t_2$ is minimized when $\sin \theta ={\upsilon }_1/{\upsilon }_2$