Fall 15 Exam #1 Form 1
1.
Wave motion transports energy from one point in space to another. When the motion of medium
is perpendicular to the direction of the wave motion, the wave is called __________.
a.
b.
c.
d.
e.
2.
170 Hz
340 Hz
680 Hz
1020 Hz
1460 Hz
A stretched string of length 0.60 meter, fixed at both ends, is vibrating in its 3rd harmonic (recall
the fundamental mode is the 1st harmonic). The wavelength of the 3rd harmonic is ____ m.
a.
b.
c.
d.
e.
6.
0.25 m
0.50 m
0.75 m
0.125 m
1.0 m
The fundamental of an organ pipe, closed at one end, is 340 Hz, and the speed of sound wave in
the pipe is 340 m/s. What is the frequency of the next harmonic of the organ pipe?
a.
b.
c.
d.
e.
5.
Universal gravitation law
Newton’s law
Diffraction
Interference
Resonance
The fundamental of an organ pipe, closed at one end, is 340 Hz; and the speed of sound wave in
the pipe is 340 m/s. What is the length of the organ pipe?
a.
b.
c.
d.
e.
4.
Longitudinal wave
Transverse wave
Diffraction wave
Space-Time wave
Diffraction wave
The phenomenon that occurs when the frequency of the driving force is the same as the "natural"
or normal frequency of the oscillating system is called __________________.
a.
b.
c.
d.
e.
3.
001
1.2 m
0.80 m
0.40 m
0.30 m
0.20 m
A stretched string of length 0.60 meter, fixed at both ends, is vibrating in its 3rd harmonic (recall
the fundamental mode is the 1st harmonic). The speed of the wave on the string is 160 m/s. The
frequency of the 3rd harmonic is
a.
b.
c.
d.
e.
200 Hz
480 Hz
128 Hz
512 Hz
400 Hz
Fall 15 Exam #1 Form 1
7.
The __________ effect is the apparent shift in frequency observed when the source or the
observer is in relative motion. When they are moving away from each other, the frequency
appears ___________; when they are moving toward each other, the frequency appears
__________.
a.
b.
c.
d.
e.
8.
002
Diffraction; higher; lower
Diffraction; lower; higher
Refraction; lower; higher
Doppler; lower; higher
Doppler; higher; lower
The trombone behaves like a pipe that is open at both ends. The lowest note that can be played
on a 9.0-ft-long trombone = __________________ Hz. (The speed of sound in air is 340 m/s)
a.
b.
c.
d.
e.
48 Hz
62 Hz
72 Hz
19 Hz
124 Hz
The oscillatory motion of simple harmonic motion is shown in the graph below, where the left
plot shows the displacement vs time, and the right plot shows the velocity vs time (in
millisecond). Answer following 2 questions.
9.
The kinetic energy of the above SHM is maximum at _______________.
a.
b.
c.
d.
e.
Time 10 ms and 20 ms
Time 5 ms and 15 ms only
Time 20 ms
Time 5 ms, 15 ms, and 25 ms
Kinetic energy does not change in simple harmonic motion.
10. The frequency of the above simple harmonic motion is ______________________.
a.
b.
c.
d.
e.
500 Hz
50 Hz
125 Hz
20 Hz
100 Hz
Fall 15 Exam #1 Form 1
003
11. In vibrating system, resonances occur at standing wave condition. Standing waves have regions
of minimum amplitude called _______ and regions of maximum amplitude called __________.
a.
b.
c.
d.
e.
Fixed end; open end
Open end; fixed end
Bulk modulus; Young’s modulus
Antinode; node
Node; antinode
12. In vibrating systems, the “time” of the repeated motion is called the __________, T. The
_________, defined as f = 1/T, has a unit of Hertz (1 Hz = 1 oscillation/second).
a.
b.
c.
d.
e.
Energy; momentum
Kinetic energy; potential energy
Energy; Friction
Period; frequency
Refraction; diffraction
13. A block of mass m = 0.250 kg hangs on a spring with spring constant k = 150 N/m and reaches
equilibrium position. The block is displaced from its equilibrium position by a distance x = 3.0
cm, and then releases it. What is the frequency of the simple harmonic motion?
a.
b.
c.
d.
e.
3.9 Hz
7.8 Hz
2.4 Hz
2.7 Hz
1.8 Hz
The displacement vs time of an object is shown in the following graph. Answer the following 2
questions
14. What is the velocity of object at t=9 s?
a. +2 m/s
b. +1 m/s
c. 0 m/s
d. ‒1 m/s
e. ‒2 m/s
15. What is the velocity of the object at t= 13 s?
a.
b.
c.
d.
e.
+2 m/s
+1 m/s
0 m/s
‒1 m/s
‒2 m/s
Fall 15 Exam #1 Form 1
004
16. When waves overlap in space and time, ______________ may be _____________that leads to a
larger wave amplitude or ______________ that leads to a smaller wave amplitude.
a.
b.
c.
d.
e.
Refraction, constructive, destructive
Diffraction, constructive, destructive
Interference, constructive, destructive
Reflection, constructive, destructive
Doppler effect, constructive, destructive
17. When wave pass through a medium with non-uniform speed, the wave can change direction in
the medium. This phenomenon is known as _________.
a.
b.
c.
d.
e.
Refraction
Interference
Doppler effect
Diffraction
Reflection
18. In simple harmonic motion (SHM), the relationship between the restoring force, F, and the
displacement, y, of the system from the equilibrium position is linear; i.e. F = ‒ky. This law in
physics is called __________.
a.
b.
c.
d.
e.
Newton’s law
Doppler’s law
Coulomb’s law
Einstein’s law
Hooke’s law
19. A nylon guitar string, 40.0 cm long, has a mass of 5.00 x 10‒4 kg and a tension of 72.0 N. What
is the frequency of the fundamental mode?
a.
b.
c.
d.
e.
100 Hz
200 Hz
300 Hz
400 Hz
600 Hz
20. A sinusoidal sound wave vs time in [millisecond] is shown below. The frequency of the wave is
a.
b.
c.
d.
e.
100 Hz
500 Hz
1000 Hz
1.0 Hz
2.0 Hz