Physics: Principles and Problems
Physics: Principles and Problems
9th Edition
Elliott, Haase, Harper, Herzog, Margaret Zorn, Nelson, Schuler, Zitzewitz
ISBN: 9780078458132
Table of contents
Textbook solutions

All Solutions

Page 675: Practice Problems

Exercise 1
Step 1
1 of 2
In order to solve this problem we are going to use the definition of the electro-motive force
$EMF=BLv$
a) Now, we can insert the values given in the problem

$$
EMF=0.4times 0.5times 20
$$

which gives that

$$
boxed{EMF=4textrm{V}}
$$

b) Now, can proceed to find the induced current in the circuit by employing Ohm’s law

$$
I=frac{EMF}{R}=frac{4}{6}
$$

so we get that

$$
boxed{I=0.67textrm{A}}
$$

Result
2 of 2
$$
textrm{a) }EMF=4textrm{V}
$$

$$
textrm{b) }I=0.67textrm{A}
$$

Exercise 2
Step 1
1 of 2
In order to solve this problem we are going to use the definition of the electro-motive force
$EMF=BLv$
Now, we can insert the values given in the problem

$$
EMF=5times 10^{-5}times 25times 125
$$

which gives that

$$
boxed{EMF=0.16textrm{V}}
$$

Result
2 of 2
$$
EMF=0.16textrm{V}
$$
Exercise 3
Step 1
1 of 6
wire + magnet + motion = induced EMF
general formula for induced EMF
Step 2
2 of 6
$$
EMF_{ind}= -BLvsintheta
$$
law of emf induced in straight wire
Step 3
3 of 6
the negative is from heinrich lenz rule
Heinrich Lenz rule : whenever an electromotive force (EMF) is induced the induced current must be in a direction such as to resist the change in magnetic flux producing it
Step 4
4 of 6
$EMF_{ind} = 1 times 30 times2 times sin(90)$ = 60 v
angle = 90 since the wire is perpendicular to magnetic flux lines
Step 5
5 of 6
$I = dfrac{V}{R} = dfrac{60}{15}$ = 4 A
from ohm’s law we get the current intensity
Ohm’s law (V=I*R)
Result
6 of 6
a) induced EMF = 60 v
b) current intensity = 4 A
Exercise 4
Step 1
1 of 2
By using the fourth-right hand rule we get that the north of the magnet has to be at the bottom.Exercise scan
Result
2 of 2
The north pole is at the bottom.
Exercise 5
Step 1
1 of 2
In order to solve this problem we are going to use the formulas for the effective voltage, effective current and Ohm’s law. So, let’s do it.

a) We start from the formula for the effective voltage which says

$$
V_{eff}=frac{sqrt{2}}{2}V_{max}
$$

So after we plug the values

$$
V_{eff}=frac{sqrt{2}}{2}170
$$

$boxed{V_{eff}=120textrm{V}}$
b) The same procedure we repeat to find the effective current

$$
I_{eff}=frac{sqrt{2}}{2}I_{max}
$$

So after we plug the values

$$
I_{eff}=frac{sqrt{2}}{2}0.7
$$

Finally, we have that
$boxed{I_{eff}=49textrm{A}}$
c) At the end, we use Ohm’s law to find the circuit resistance

$$
R=frac{V_{eff}}{I_{eff}}=frac{120}{49}
$$

$$
boxed{R=240Omega}
$$

Result
2 of 2
$$
textrm{a) }V_{eff}=120textrm{V}
$$

$$
textrm{b) }I_{eff}=49textrm{A}
$$

$$
textrm{c) }R=240Omega
$$

Exercise 6
Step 1
1 of 2
In order to solve this problem we are going to use the formulas for the effective voltage and effective current. So, let’s do it. We start from the formula for the effective (RMS) voltage which says

$$
V_{RMS}=frac{sqrt{2}}{2}V_{max}
$$

We can express the maximum voltage as follows

$$
V_{max}=sqrt{2}V_{RMS}
$$

So after we plug the values

$$
V_{max}=sqrt{2}times 117
$$

$$
boxed{V_{max}=165textrm{V}}
$$

The same procedure we repeat to find the maximum current

$$
I_{RMS}=frac{sqrt{2}}{2}I_{max}
$$

$$
I_{max}=sqrt{2}I_{RMS}
$$

So after we plug the values

$$
I_{max}=sqrt{2}times 5.5
$$

$$
boxed{I_{max}=7.76textrm{A}}
$$

Result
2 of 2
$$
V_{max}=165textrm{V}
$$

$$
I_{max}=7.76textrm{A}
$$

Exercise 7
Step 1
1 of 2
In order to solve this problem we are going to use the formulas for the effective voltage, effective current and Ohm’s law. So, let’s do it.

a) We start from the formula for the effective voltage which says

$$
V_{eff}=frac{sqrt{2}}{2}V_{max}
$$

So after we plug the values

$$
V_{eff}=frac{sqrt{2}}{2}425
$$

$boxed{V_{eff}=300textrm{V}}$
b) Now, we can use Ohm’s law to find the effective current

$$
I_{eff}=frac{V_{eff}}{R}=frac{300}{500}
$$

$$
boxed{I_{eff}=0.6textrm{A}}
$$

Result
2 of 2
$$
textrm{a) }V_{eff}=300textrm{V}
$$

$$
textrm{b) }I_{eff}=0.6textrm{A}
$$

Exercise 8
Step 1
1 of 2
In order to solve this problem we are going to use the formulas for the average/effective voltages and currents. Since the power is given as

$$
P=Itimes V
$$

then the effective power is given as

$$
P_{eff}=I_{eff}V_{eff}=frac{sqrt{2}}{2}I_{max}times frac{sqrt{2}}{2}V_{max}
$$

This gives that

$$
P_{eff}=frac{P_{max}}{2}
$$

Now, we can express the maximum power as

$$
P_{max}=2P_{eff}=2times 75
$$

Finally,

$$
boxed{P_{max}=150textrm{W}}
$$

Result
2 of 2
$$
P_{max}=150textrm{W}
$$
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Section 1.1: Mathematics and Physics
Section 1.2: Measurement
Section 1.3: Graphing Data
Page 24: Assessment
Page 29: Standardized Test Practice
Chapter 3: Accelerated Motion
Section 3.1: Acceleration
Section 3.2: Motion with Constant Acceleration
Section 3.3: Free Fall
Page 80: Assessment
Page 85: Standardized Test Practice
Chapter 4: Forces in One Dimension
Section 4.1: Force and Motion
Section 4.2: Using Newton’s Laws
Section 4.3: Interaction Forces
Page 112: Assessment
Page 117: Standardized Test Practice
Chapter 5: Forces in Two Dimensions
Section 5.1: Vectors
Section 5.2: Friction
Section 5.3: Force and Motion in Two Dimensions
Page 140: Assessment
Page 145: Standardized Test Practice
Chapter 6: Motion in Two Dimensions
Section 6.1: Projectile Motion
Section 6.2: Circular Motion
Section 6.3: Relative Velocity
Page 164: Assessment
Page 169: Standardized Test Practice
Chapter 7: Gravitation
Section 7.1: Planetary Motion and Gravitation
Section 7.2: Using the Law of Universal Gravitation
Page 190: Assessment
Page 195: Standardized Test Practice
Chapter 8: Rotational Motion
Section 8.1: Describing Rotational Motion
Section 8.2: Rotational Dynamics
Section 8.3: Equilibrium
Page 222: Assessment
Page 227: Standardized Test Practice
Chapter 9: Momentum and Its Conservation
Chapter 10: Energy, Work, and Simple Machines
Section 10.1: Energy and Work
Section 10.2: Machines
Page 278: Assessment
Page 283: Standardized Test Practice
Chapter 11: Energy and Its Conservation
Section 11.1: The Many Forms of Energy
Section 11.2: Conservation of Energy
Page 306: Assessment
Page 311: Standardized Test Practice
Chapter 13: State of Matter
Section 13.1: Properties of Fluids
Section 13.2: Forces Within Liquids
Section 13.3: Fluids at Rest and in Motion
Section 13.4: Solids
Page 368: Assessment
Page 373: Standardized Test Practice
Chapter 14: Vibrations and Waves
Section 14.1: Periodic Motion
Section 14.2: Wave Properties
Section 14.3: Wave Behavior
Page 396: Assessment
Page 401: Section Review
Chapter 15: Sound
Section 15.1: Properties of Detection of Sound
Section 15.2: The Physics of Music
Page 424: Assessment
Page 429: Standardized Test Practice
Chapter 17: Reflections and Mirrors
Section 17.1: Reflection from Plane Mirrors
Section 17.2: Curved Mirrors
Page 478: Assessment
Page 483: Standardized Test Practice
Chapter 18: Refraction and lenses
Section 18.1: Refraction of Light
Section 18.2: Convex and Concave Lenses
Section 18.3: Applications of Lenses
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Page 513: Standardized Test Practice
Chapter 21: Electric Fields
Section 21.1: Creating and Measuring Electric Fields
Section 21.2: Applications of Electric Fields
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Page 589: Standardized Test Practice
Chapter 22: Current Electricity
Section 22.1: Current and Circuits
Section 22.2: Using Electric Energy
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Page 615: Standardized Test Practice
Chapter 23: Series and Parallel Circuits
Section 23.1: Simple Circuits
Section 23.2: Applications of Circuits
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Page 641: Standardized Test Practice
Chapter 24: Magnetic Fields
Section 24.1: Magnets: Permanent and Temporary
Section 24.2: Forces Caused by Magnetic Fields
Page 664: Assessment
Page 669: Standardized Test Practice
Chapter 25: Electromagnetic Induction
Section 25.1: Electric Current from Changing Magnetic Fields
Section 25.2: Changing Magnetic Fields Induce EMF
Page 690: Assessment
Page 695: Standardized Test Practice
Chapter 30: Nuclear Physics
Section 30.1: The Nucleus
Section 30.2: Nuclear Decay and Reactions
Section 30.3: The Building Blocks of Matter
Page 828: Assessment
Page 831: Standardized Test Practice