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 700: Practice Problems

Exercise 1
Step 1
1 of 2
In order to solve this problem we are going to use Newton’s second law which says that on a circular path it has to hold that

$$
qvB=frac{mv^2}{r}
$$

From here, we can express the radius to have that

$$
r=frac{mv}{qB}=frac{1.67times 10^{-27}times 7.5times 10^3}{1.6times 10^{-19}times 0.6}
$$

Finally, we have that

$$
boxed{r=1.3times 10^{-4}textrm{ m}}
$$

Result
2 of 2
$$
r=1.3times 10^{-4}textrm{ m}
$$
Exercise 2
Step 1
1 of 2
In order to solve this problem we are going to use Newton’s third law which says that in equilibrium it has to hold that

$$
qvB=qE
$$

Which gives that the speed is given as

$$
v=frac{E}{B}
$$

So after we plug in the values

$$
v=frac{3000}{0.06}
$$

Finally

$$
boxed{v=50times 10^3frac{textrm{m}}{textrm{s}}}
$$

Result
2 of 2
$$
v=50times 10^3frac{textrm{m}}{textrm{s}}
$$
Exercise 3
Step 1
1 of 2
In order to solve this problem, we are going to use Newton’s second law which says that on a circular path it has to hold that

$$
qvB=frac{mv^2}{r}
$$

However, we have to find the speed first. The speed is obtained while the electric field is acting on the electron
third law which says that in equilibrium it has to hold that

$$
qvB=qE
$$

Which gives that the speed is given as

$$
v=frac{E}{B}
$$

So after we plug in the values

$$
v=frac{3000}{0.06}=50times 10^3frac{textrm{m}}{textrm{s}}
$$

Now, we can express the radius to have that

$$
r=frac{mv}{qB}=frac{9.11times 10^{-31}times 50times 10^3}{1.6times 10^{-19}times 0.06}
$$

Finally, we have that

$$
boxed{r=4.7times 10^{-6}textrm{ m}}
$$

Result
2 of 2
$$
r=4.7times 10^{-6}textrm{ m}
$$
Exercise 4
Step 1
1 of 2
In order to solve this problem we are going to use Newton’s third law which says that in equilibrium it has to hold that

$$
qvB=qE
$$

Which gives that the speed is given as

$$
v=frac{E}{B}
$$

So after we plug in the values

$$
v=frac{4500}{0.6}
$$

Finally

$$
boxed{v=7.5times 10^3frac{textrm{m}}{textrm{s}}}
$$

Result
2 of 2
$$
v=7.5times 10^3frac{textrm{m}}{textrm{s}}
$$
Exercise 5
Step 1
1 of 2
In order to solve this problem, we are going to use Newton’s second law which says that on a circular path it has to hold that

$$
qvB=frac{mv^2}{r}
$$

However, we have to find the speed first. The final speed of the oxygen atoms is the consequence of the acceleration in the electric field which is expressed via the conservation of energy

$$
qV=frac{mv^2}{2}
$$

where we can express the square of the speed as

$$
v^2=frac{2qV}{m}
$$

Now, we will square our first equation and plug in the last expression into it

$$
q^2v^2B^2=frac{m^2v^4}{r^2}
$$

$$
q^2B^2=frac{m^2v^2}{r^2}=frac{m^2}{r^2}frac{2qV}{m}
$$

After some simple algebra one gets that

$$
qB^2=frac{2mV}{r^2}
$$

So we can express the mass as

$$
m=frac{qr^2B^2}{2V}=frac{1.6times 10^{-19}times 0.085^2times 0.072^2}{2times 110}
$$

Finally, we have that

$$
boxed{m=2.7times 10^{-26}textrm{ kg}}
$$

Result
2 of 2
$$
m=2.7times 10^{-26}textrm{ kg}
$$
Exercise 6
Step 1
1 of 2
In order to solve this problem, we are going to use Newton’s second law which says that on a circular path it has to hold that

$$
qvB=frac{mv^2}{r}
$$

However, we have to find the speed first. The final speed of the argon atoms is the consequence of the acceleration in the electric field which is expressed via the conservation of energy

$$
qV=frac{mv^2}{2}
$$

where we can express the square of the speed as

$$
v^2=frac{2qV}{m}
$$

Now, we will square our first equation and plug in the last expression into it

$$
q^2v^2B^2=frac{m^2v^4}{r^2}
$$

$$
q^2B^2=frac{m^2v^2}{r^2}=frac{m^2}{r^2}frac{2qV}{m}
$$

After some simple algebra one gets that

$$
qB^2=frac{2mV}{r^2}
$$

So we can express the mass as

$$
m=frac{qr^2B^2}{2V}=frac{2times1.6times 10^{-19}times 0.106^2times 0.05^2}{2times 66}
$$

Finally, we have that

$$
boxed{m=6.8times 10^{-26}textrm{ kg}}
$$

Result
2 of 2
$$
m=6.8times 10^{-26}textrm{ kg}
$$
Exercise 7
Step 1
1 of 2
In order to solve this problem we are going to use Newton’s third law which says that in equilibrium it has to hold that

$$
qvB=qE
$$

Which gives that the speed is given as

$$
v=frac{E}{B}
$$

So after we plug in the values

$$
v=frac{600}{0.0015}
$$

Finally

$$
boxed{v=400times 10^3frac{textrm{m}}{textrm{s}}}
$$

Result
2 of 2
$$
v=400times 10^3frac{textrm{m}}{textrm{s}}
$$
Exercise 8
Step 1
1 of 2
In order to solve this problem, one has to understand that apart from the mass of the atoms, other parameters are the same and this results in different radii. From the charge-to-mass ratio, we have that

$$
frac{q}{m}=frac{2V}{r^2B^2}
$$

So we have that

$$
rpropto sqrt{m}
$$

Now, the ratio between the two isotopes is

$$
frac{r_{22}}{r_{20}}=sqrt{frac{m_{22}}{m_{20}}}
$$

We can express then the radii of the heavier isotope

$$
r_{22}=sqrt{frac{m_{22}}{m_{20}}}r_{20}=sqrt{frac{22}{20}}times 0.053
$$

Finally, we have that

$$
r_{22}=0.056textrm{ m}
$$

Now, the distance between the landing points of the two isotopes is equal to

$$
d=2(r_{22}-r_{20})=2times(0.056-0.053)
$$

So at the end we obtain

$$
boxed{d=0.006textrm{ m}}
$$

Result
2 of 2
$$
d=0.006textrm{ m}
$$
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Chapter 1: A Physics Toolkit
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
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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
Page 508: Assessment
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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Chapter 24: Magnetic Fields
Section 24.1: Magnets: Permanent and Temporary
Section 24.2: Forces Caused by Magnetic Fields
Page 664: Assessment
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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