Physics 121P, Spring 2014
Unit 7
Unit 7 Work and Energy (chapter 7, Fundamentals of Physics 10th edition)
Introduction
The previous units have led up to an understanding of Newtons Laws of motion,
which contain all of the information needed to predict the
Physics 121P, Spring 2014
Unit 1
Unit 1 Measurement, Numbers, and Physical Units
Introduction
Chapter 1 - Fundamentals of Physics (10th edition).
As a physicist, one tries to make observations of the surrounding universe which can be
expressed as numbers.
PHY 122 HW 8 Solutions
1. For each of the following pairs of vectors ~a and ~b:
(a) What is the direction of the vector ~a ~b ( means a vector pointing out of the page)?
(b) Taking the magnitudes of ~a and ~b to be equal, rank their cross products in orde
Physics 122 Homework # 3
1. What do we mean by:
V (~r) =
U (~r)
q
and how is it analogous to the electric field and the electrostatic force?
Solution: If charge Q is the source of an electric potential V (r), and a charge q is within that electric potent
PHY 122 HW 11 Solutions
1. Youre in your lab, when the machine you are using breaks down! You manage to figure out that the inductor in one
of the circuits fried. You dont know the inductance it had, but you know it produced a peak emf of 150 mV from a
cu
Physics 122 Homework # 3
1. What does the following equation mean and how is it analogous to the relationship between the electric field and the
the electrostatic force?
V (~r) =
U (~r)
q
2. Consider the charge distribution from HW 2, problem 2, shown bel
PHY 122 HW 4
1. If we multiply 1 Coulomb by 1 Volt, what type of quantity are we left with (i.e.
force, power, distance, etc)? How does this quantity relate to an electron volt?
2. As a simple model of lightning, we can approximate a storm cloud and the
g
PHY 122 HW 8
1. For each of the following pairs of vectors ~a and ~b:
(a) What is the direction of the vector ~a ~b ( means a vector pointing out of the page)?
(b) Taking the magnitudes of ~a and ~b to be equal, rank their cross products in order of ascen
PHY 122 HW 6
1. Explain the difference between EMF and terminal voltage in an ideal battery.
Give an example where the difference between the two might matter.
2. Using the diagram below, answer questions (a) through (c):
(a) What is the equivalent resist
PHY 122 HW 1
1. We have seen that Coulombs Law, FE = kQr12Q2 where k = 9 109
m2
Law of Gravitation, FG = Gmr12m2 where G = 6.67 1011 Nkg
2 .
N m2
C2 ,
appears to be very similar to Newtons
(a) Approximately how many times larger is k than G?
(b) Consider
PHY 122 HW 11
1. Youre in your lab, when the machine you are using breaks down! You manage to figure out that the inductor in one
of the circuits fried. You dont know the inductance it had, but you know it produced a peak emf of 150 mV from a
current of t
PHY 122 HW 10 Solutions
1. What is the distinction between which side of a transformer is the primary or secondary coil? Could it easily be
switched around and operated the opposite way? What would change?
Solution: The primary coil is connected to an in
PHY 122 HW 7
~ which is perpendicular to the particles velocity, ~v . Will its
1. An electron enters a region of uniform magnetic field, B,
kinetic energy increase, decrease, or stay the same? Explain.
2. The same electron as above spends a time of t in t
PHY 122 HW 9
1. Describe the difference (in any) in the induced current in a wire loop when a magnet goes through the loop north side
first, south side first, and sideways.
2. A long straight wire oriented in the z direction carries a current I. A square
PHY 122 HW 6 Solutions
1. Explain the difference between EMF and terminal voltage in an ideal battery.
Give an example where the difference between the two might matter.
Solution: The EMF () is the potential difference between the terminals
when no curre
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PHY 122 HW 1 Solutions
2
1. We have seen that Coulombs Law (k Qr1 Q
, k = 9 109
2
m2
2
Gravitation (G Mr1 M
, G = 6.67 1011 Nkg
2
2 ).
N m2
C2 )
appears to be very similar to Newtons Law of
(a) Approximately how many times larger is k than G?
(b) Take 2 e
PHY 122 HW 2 Solutions
1. For a spherical surface centered around a point charge, the formula for electric flux E = E dA simplifies to
E = EA. Why? If our spherical surface is surrounding an electric dipole rather than a point charge, this simplification
PHY 122 HW 5
1. A square parallel plate capacitor has sides with a length of 1cm and a separation
between the plates of 1 m. If we fill the capacitor with a dielectric in order to
achieve a capacitance of 0.1 F, what does the dielectric constant need to b
PHY 122 HW 12
1. For the circuit below, draw phasors for I1 , I2 with Vab . Hint: start with Vab and I1 . Write an expression relating I1 and
I2 .
2. You are being held hostage on a jungle island by guerillas, not gorillas (bonus points if you know what m
PHY 122 HW 4 Solutions
1. If we multiply 1 Coulomb by 1 Volt, what type of quantity are we left with (i.e.
force, power, distance, etc)? How does this quantity relate to an electron volt?
Concepts
Units
Electric Potential
Electric Potential Energy
Ta
PHY 122 HW 2
1. For a spherical surface centered around a point charge, the formula for electric flux E = E dA simplifies to
E = EA. Why? If our spherical surface is surrounding an electric dipole rather than a point charge, this simplification
does not w
PHY 122 HW 7
~ which is perpendicular to the particles velocity, ~v . Will its
1. An electron enters a region of uniform magnetic field, B,
kinetic energy increase, decrease, or stay the same? Explain.
Solution: Since the particle is in circular motion,
PHY 122 HW 10
1. What is the distinction between which side of a transformer is the primary or secondary coil? Could it easily be
switched around and operated the opposite way? What would change?
2. Power lines that deliver power to your dorms are held at
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Last Revised on September 10, 2013
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E XPERIMENT 5
The Equivalence of Energy: Heat,
Mechanical, Electrical, and
Light
0. Pre-Laboratory Work [2pts]
1. A 90kg person jumps from a
Physics 121P, Spring 2014
Unit 10
Unit 10 Collisions
Introduction (Fundamentals of Physics, 10th edition Chapter 9 second half- updated)
An example of the use of the conservation laws which occurs frequently in physics is in
the study of collisions. If tw
Physics 121P, Spring 2014
Unit 9
Unit 9 The Center of Mass and Conservation of Linear Momentum
Introduction (Fundamentals of Physics, 10th edition Chapter 9 Linear Momentum)
When you apply Newtons second law to an object like the moon, what point of the
o