[1] Choose the correct answer for the following:
(4 marks)
1- A traveling wave that causes the elements of the medium to move parallel to the
direction of propagation is called:
A linear wave.
B sinusoidal wave.
C transverse wave.
D longitudinal wave.
2- As a wave moves between the media:
A its wavelength remains constant.
B its frequency remains constant.
C its wave number remains constant.
D its speed remains constant.
3- Total internal reflection occurs when light travels:
A from a medium of low index of refraction to one of higher index of refraction.
B from a medium of high index of refraction to one of lower index of refraction.
C from a medium of high thickness to one of lower thickness.
D from a medium of low optical density to one of higher optical density.
4- The unit used for measuring the sound level is:
A meters.
B seconds.
C decibels.
D Hertz.
[2] Prove that the speed of a wave traveling on a taut string of mass per unit length 
and tension T is
𝑻
𝒗 = √𝝁
(4 marks)
[3] Two ships are moving along a line due east. The trailing ship has a speed relative to
a land-based observation point of 20.55 m/s, and the leading ship has a speed of 15.3
m/s relative to that point. The trailing ship transmits a sonar signal at a frequency of
1200 Hz. What frequency is monitored by the leading ship?
(the speed of sound in ocean water = 1520 m/s)
(4 marks)
[4] A sinusoidal wave of wavelength 2 m and amplitude 0.1 m travels on a string with a
speed of 1 m/s to the right. Initially, the left end of the string is at the origin. Find (a)
the frequency and angular frequency, (b) the angular wave number, and (c) the wave
function for this wave.
(4 marks)
[5] A laser beam is incident at an angle of 30° from the vertical onto a solution of corn
syrup in water. If the beam is refracted to 19.24° from the vertical, (a) what is the index
of refraction of the syrup solution? Suppose the light is red, with vacuum wavelength
632.8 nm. Find its (b) wavelength, (c) frequency, and (d) speed in the solution.
(nwater = 1.33 ,
Speed of light in vacuum C = 3x108 m/s)
(4 marks)