Aptitude Test Problems in Physics Science for Everyone by S Krotov ( PDFDrive.com )

Solutions 305

to the bisector of the angle a, and then move along
the shore in the direction of point B.

Fig. 240

The angle y can be determined from Snell's law

(n = 2):

sin y = n sin + c

The distance a is

I/ I —n 2 sine (a/2)

The distance b can be determined from the equa-

tion a b = 3/12 — h 2. Hence

n sin (a/2)

b= `1,/ 1 2 --h 2 h

n (^2) sin 2 (a12)
If b > 0, i.e. / 2 — h 2 > h2
y
_ r
1 — n 2 sine (a/2)
the fisherman must use the boat. Separate segments
in this case will be
a
ER=p.b sin 2
n sin (a/ (^2) ) (^) ) sin it
= (^) h2 (^) 1/- 1 -
_n2 sine (a/2) 2
AE = q =
cos y (^) 1—ns sine (a/2)
n sin (a/2)
h tan 7=-- h
—n 2 sine (a/2)