Chapter 4
Dynamics Newton's Laws of Motion
1.
Assume that a hockey puck slides
across ice on a horizontal plane. Do not ignore friction.
Indicate
which of the following free body diagrams is correct by placing a check (P
) mark by the appropriate one: A, B, or C
A___________
B__________
C.______
P_______
2. A box is on a plane at an angle of 23 degrees to the horizontal. The coefficient of kinetic friction of the plane is 0.13. The mass of the box is 2 kg. The front of the box is 9.1
meters
from the bottom of the incline. The box starts from rest.
a. Draw a
free-body diagram to include angles, forces, coordinate system, etc.
b. Write the
equation, using Newton’s law(s) for the summation of forces in the x
direction. Insert values but do not evaluate the expression.
mg
3. The free body diagram for a system (object on a flat table being pulled by the indicated force) is shown below, along with the coordinate system to use.
SFx
=
b. Using the appropriate laws of Newton, write an expression for the
summation of the forces in the y direction.
SFy
=
|
4.
Given the axes shown on the right, with y as the vertical axis. The
a.
x as the horizontal axis and plot y = x
b.
x as the horizontal axis and plot y = x2
c. x2 as the horizontal axis and plot y = x2 |
 |
Which of the above plots will result in a
straight line?
A.
a only B.
b only
C. c only
D. a and b only
E. a and c only
Answer
5.
State Newton's first law in words, not equations.
The
acceleration of an object is directly proportional to the net force acting
on it, and is inversely proportional to its mass. The direction of the
acceleration is the direction of the net force acting on the object.
|
8. One of the many important concept in physics that was addressed
by Sir Isaac Newton is the _____________________ reference frame.
inertial
In my manual I discuss the picture shown below
A reference frame attached to one of the seats is not this type of
reference frame.
|
Chapter 11
Vibrations and Waves
1. The time for one cycle of a
periodic process is called the
A) amplitude.
B)
wavelength.
C)
frequency. D) period.
Answer:
D
2. For a periodic process, the
number of cycles per unit time is called the
A) amplitude.
B)
wavelength.
C)
frequency.
Answer: C
D) period.
3. For vibrational motion, the
maximum displacement from the equilibrium point is called the
A) amplitude.
Answer:
A
B) wavelength C) frequency
D) period.
.
4. A mass on a spring undergoes
SHM. When the mass is at its
maximum displacement from
equilibrium, its instantaneous velocity
A) is maximum.
C)
is zero.
Answer:
C
B) less than maximum, not zero.
D)
cannot be determined from the information given.
5. A mass on a spring undergoes
SHM. When the mass passes
through the equilibrium position, its
A) is maximum.
Answer:
A
C) is zero.
B) less than maximum, not zero.
D)
cannot be determined from the information given.
6. If you take a given pendulum
to the Moon, where the acceleration of gravity is less than on Earth,
the resonant frequency of the pendulum will
A) increase.
C)
not change
B) decrease.
Answer:
B
D) either increase or decrease; depends on its length to mass ratio.
|
7.
Curve A in the figure on the right represents
A) an
underdamped situation.
Answer: A
B) an overdamped
situation.
C) a moderately damped situation.
D) critical damping.
|
|
|
8. The distance
indicated by the arrow shown on the the figure
below is called the wave's
A) speed.
C)
wavelength
Answer: C
B) frequency.
D)
amplitude |
|
|
 |
||
9. The number of crests of a
wave passing a point per unit time is called the wave's
A) speed.
B)
frequency.
Answer:
B
C)
wavelength
D) amplitude.
10. The frequency of a wave
increases. What happens to the
distance between successive crests if
the speed remains constant?
A) It increases.
C)
It decreases.
Answer:
C
B) It remains the same.
D)
It cannot be determined from the information given
11. A string of mass m and length L is under tension T. The speed of a wave in the string is v. What will be the speed of a wave in the string if the mass of the string is
increased to 2m, with no
change in length?
A) 0.5v
B)
0.71v
Answer:
B
C)
1.4v
D) 2v
12. The intensity of a wave is
A) proportional to both the amplitude squared and the frequency squared
Answer:
A
B) proportional to the amplitude squared and inversely proportional to the
frequency squared.
C) inversely proportional to the amplitude squared and proportional to the
frequency squared.
D) inversely proportional to both the amplitude squared and the frequency
squared.
13. A mass on a spring
undergoes SHM. It goes through
10 complete oscillations in 5.0 s. What is
the period?
A) 0.020 s
B)
0.50 s
Answer:
B
C)
2.0 s
D) 50 s
14. A simple pendulum consists of a 0.25-kg spherical mass attached to a massless string. When the mass is displaced slightly from its equilibrium position and released, the
pendulum swings back and forth with a frequency of 2.0 Hz. What frequency would have resulted if a 0.50-kg mass (same diameter sphere) had been attached to the string
instead?
A) 1.0 Hz
B)
2.0 Hz
Answer:
B
C)
1.4 Hz
D) none of the above
|
15. This figure is a
"snapshot" of a wave at a
given time. The
frequency of the wave is 120
Hz. What is the
amplitude?
A) 0.05 m
C)
0.15 m
B) 0.10 m
Answer:
B
D) 0.20 m
|
|
A) 4.0 m/s
B)
9.0 m/s
C)
15 m/s
D) 36 m/s
Answer: D
Chapter 21
Electromagnetic Induction and Faraday's Law
1. Faraday's law of induction
states that the emf induced in a loop of wire is proportional to
A) the magnetic flux.
B) the magnetic flux density times the loop's area.
C) the time variation of the magnetic flux.
Answer:
C
D) current divided by time.
2. Doubling the number of loops
of wire in a coil produces what kind of change on the induced emf,
assuming all other factors remain constant?
A) The induced emf is 4 times as much.
B)
The induced emf is twice times as much.
Answer:
B
C)
The induced emf is half as much.
D)
There is no change in the induced emf.
3. As a coil is removed from a magnetic field an emf is induced in the coil causing a current to flow within the coil. This current interacts with the magnetic field producing a
force which
A) acts at right angles to the coil's motion.
C)
causes the coil to tend to flip over.
B)
acts in the direction of the coil's motion.
D)
acts in direction opposite to coil's motion.
Answer
D
4. A circular coil lies flat on a horizontal table. A bar magnet is held above its center with its north pole pointing down. The stationary magnet induces (when viewed from
above)
A) no current in the coil.
Answer:
A
B) a clockwise current in the coil.
C) a counterclockwise current in the coil.
D) a current whose direction cannot be determined from the information
given.
5. A coil lies flat on a level table top in a region where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above,
what is the direction of the
induced current in this coil as the field increases?
A) counterclockwise
B) clockwise
Answer:
B
C) clockwise initially, then counterclockwise before stopping
D) There is no induced current in this coil.
6. A coil lies flat on a horizontal table top in a region where the magnetic field points straight down. The magnetic field disappears suddenly. When viewed from above,
what is the direction of the
induced current in this coil as the field disappears?
A) counterclockwise
B) clockwise
Answer:
B
C) clockwise initially, then counterclockwise before stopping
D) There is no induced current in this coil.
7. A generator coil rotates
through 60 revolutions each second.
The frequency of the emf is
A) 30 Hz.
C)
120 Hz.
B) 60 Hz.
Answer:
B
D) cannot be determined from the information given.
8. A transformer is a device
used to
A) transform an alternating current into a direct current.
B) transform a direct current into an alternating current.
C) increase or decrease an ac voltage.
Answer:
C
D) increase or decrease a dc voltage.
9. A flux of 4.0 × 10-5 Wb
is maintained through a coil for 0.50 s.
What emf is induced in this coil by
this flux?
A) 8.0 × 10-5 V
B)
4.0 × 10-5 V
C)
2.0 × 10-5 V
D) No emf is induced in this coil.
Answer
D
10. A circular loop of radius 0.10 m is rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field
vector
are
parallel.
A) zero
Answer:
A
B) 3.1 × 10-3 T∙m2
C) 5.5 × 10-3 T∙m2
D) 6.3 × 10-3 T∙m2
11. The cross-sectional area of
an adjustable single loop is reduced from 1.0 m2 to
0.50 m2 in
0.10 s.
What is the average emf that is induced in this coil if it is in a region
where B = 2.0 T upward, and
the coil's plane is perpendicular to B?
A) 5 V
B)
10 V
Answer:
B
C) 15 V
D)
20 V
12. A square coil of wire with 15 turns and an area of 0.40 m2 is placed parallel to a magnetic field of 0.75 T. The coil is flipped so its plane is perpendicular to the magnetic
field
in 0.050 s. What is
the magnitude of the average induced emf?
A) 6.0 V
B)
36 V
C)
45 V D)
90 V
Answer:
D
Extra Credit
1.
“Genius is 1 percent inspiration and 99 percent perspiration.” is a quote
from
___________________________
Thomas Edison
2.
_____________________________ is considered the "Father of AC".
He won the "war of
currents".
Nikola Tesla
3. The work of ____________________________________ in producing a unified model of electromagnetism is considered to be one of the greatest advances in physics.
His
picture, along
with the physics giant in question 5 below, was in the study of Albert
Einstein, along with that of
Sir Isaac Newton.
James Clerk Maxwell
|
4. My picture
is on the right. It was also in the study of Albert Einstein.
I studied the magnetic field around a conductor carrying a DC electric current, and
established the basis for the magnetic field concept in
I discovered
electromagnetic induction, and laws
of electrolysis.
My name is __________________________________
Michael Faraday
|
||
|
5. A picture of an ______________________ is shown on the right. It is an instrument for detecting the presence of static electricity. It consists of two thin metal leaves
suspended
from a metal hook.
electroscope or
Leyden jar the hook are pushed to the leaves (if the source is negative) or pulled up to the hook
from
the leaves (if the
source is positive). Either way, the leaves are now charged the
|
|
|
