Physics 1112
Homework #1B Solutions
#1[Airplane in the Wind]
Speed of the plane with respect to air vP/A = 135 mi/h and speed of wind with respect to the ground
vA/G = 30 mi/h. The x-components of vP/A and vA/G must have equal magnitude. So, 135 sin() =
3
Phys 1112 Homework #2 Solutions
Extra Practice Questions:
#3.30 [Hypergravity]
The arm has a length of R = 8.84 m and the astronauts head is at the outermost point on the arm.
The astronaut is 2.00 m tall. The maximum acceleration is 12.5 g.
(a) To achiev
Section: _
Name: _
Section Instructor: _
Physics 1112
Assignment #6
Concepts:
Energy graphs
Impulse and momentum
Power
Collisions
Reading in text: Chapter 6, sections 4; Chapter 7, sections 4-5; Chapter 8, sections 1-5.
Assignment: Due in your second sect
Molecular Kinetic Theory of Ideal Gases
GOALS for this class:
* Review the Ideal Gas Law, what it means physically, and
ways to summarize it using graphs.
* Develop the Kinetic Theory of Ideal Gases by using
mechanics principles to explain gas properties
PE, Force, & Energy Diagrams
GOALS for this class:
* Examine the mathematical and physical relationships
between conservative force and potential energy.
* Explore the use of Potential Energy Graphs to illustrate
relationships between PE, KE, total mechan
Rotational Kinematics
GOALS for this class:
* Identify useful variables to describe rotational motion.
* Establish and apply basic mathematical relations for
rotational kinematics.
* Formulate and apply principles and notation for
representing kinetic ene
Temperature & Heat
GOALS for this class:
* Examine the meaning of and relationships between
temperature, heat, and thermodynamic equilibrium.
* Review the Ideal Gas Law as an example of using
thermodynamic variables.
* Define specific heat, heat capacity,
Phys 1112 Study Hall Hours
Thursday
294B
Kunal Shah
Jaeyoon Lee
Yi Xue Chong
3:30 4:30
Brian Schaefer and Celesta Chang
Celesta Chang
5:30 6:30
294B
3:30 5:30
4:30 5:30
Wednesday
Sal Lombardo
5:30 7:30
294B
Jaeyoon Lee
4:30 5:30
Tuesday
Dan Quach
3:00 4:0
Homework #6B
Physics 1112
References:
Chap. 7, sections 7.2 thru 7.5
Physics Ideas:
Math Skills:
Fall 2014
Gravitational & Elastic Potential Energies; Conservation of Energy
Potential Energy Graphs and relations between PE & Force
Geometry, Trigonometry,
Phys 1112 Homework #6A Solutions
#6.4 [Pushing a Crate] m 30.0kg, 30 , k 0.25
F
y
m
N
fk
k
x
mg
F
(a) From the free-body diagram:
x-component: F cos f k 0
y-component: N F sin mg 0
The frictional force is: f k k N , so f k k ( F sin mg) , where the y-comp
Phys 1112 Homework #5 Solutions
#5.46 [Giant Swing Ride]
2
The acceleration of the person is arad v /R, directed horizontally to the left in the
2 R
. Apply
figure in the problem. The time for one revolution is the period T
v
F ma to the person. The pers
Phys 1112 Homework #6B Solutions
m
#7.19 [Spring + book]
(a) For Us = 3.20 J, the compression distance is found using
H
h
2U s
2 3.20 J
6.3cm .
k
1600 N / m
1
U s k x 2 . So x
2
m
k
k
(b) We take the lowest point the spring reaches as
the point where Ug
Phys 1112 Homework #7 Solutions
#6.94 [Hydropower]
The electrical power output from a 170 m high dam is 2000 MW. The density of the water is
given as 1000 kg/m3. From the lecture notes, the available power is
U g m gh W V gh
V
. The electrical power outpu
Phys 1112 Homework #8 Solutions
#8.93 [Neutron-Nucleus Collision]
M
(a) The initial kinetic energy of the
m
v0
neutron is K0 . The kinetic energy
that it loses in the collision is just
Neutron
the kinetic energy the nucleus gains.
Nucleus
For a 1-D elasti
Energy & Work
GOALS for this class:
* Examine an alternate view of dynamics using the
concepts of Work and Energy.
* Define mechanical work, and derive expressions for
work done by various common forces gravity,
elastic, friction, drag, constraint forces.
1st Law of Thermodynamics
GOALS for this class:
* Develop an expression for thermodynamic work, and
calculate it for various thermodynamic processes.
* Develop and apply the 1st Law of Thermodynamics,
relating heat, work, and internal energy.
* Examine th
Possibly Useful Information:
!
!
!r
!v
!
!
v av =
aav =
!t
!t
!
!
! dv
! dr
v=
a=
dt
dt
!
!
!
!
!r = " v dt
!v = " adt
W =
GMm
= mg = w
r2
!
!
v2
a = R
1
fk = kN
!
!
FA on B = ! FBon A
F = kx
fd = bv
fr = r N
fd = 2 CAv2
m
= V
1
1
! F ds
dv
a| = dt
vx2(t
Momentum & Impulse
GOALS for this class:
* Define momentum and impulse, see how they are
related by the Impulse-Momentum Theorem, and
use these ideas to analyze physical behaviors.
* Apply the principle of Conservation of Momentum, and
note limitations on
Power
GOALS for this class:
* Define power and develop methods for calculating
power delivered or dissipated in mechanical systems.
* Examine energy and power requirements for automobile
transportation acceleration, hill climbing, rolling
resistance, air
Collisions
GOALS for this class:
* Apply principles of Momentum, Impulse, Kinetic Energy,
and Conservation of Momentum to collision processes.
* Define and characterize different kinds of Collisions:
elastic, inelastic, superelastic.
* Predict behaviors
Recoil & Propulsion
GOALS for this class:
* Examine how momentum and recoil are used in propulsion.
* Explore rocket propulsion and its application to
space travel.
1
Turbofan Engines
p
p
air(fuel)out
airin
F
thrust
p
airin
p
air(fuel)out
t
2
1
Ex. A
Driven Simple Harmonic Motion & Resonance
GOALS for this class:
* Examine the motion of a simple harmonic oscillator
(SHO) driven by Simple Harmonic Motion (SHM).
* Explore how the response amplitude of a SHO
driven by SHM depends on the driving frequency
Gyroscopes & Precession
GOALS for this class:
* Apply the relationship between torque and angular
momentum when these vectors are not parallel.
* Investigate the roles of angular momentum and torque
in gyroscopes and the process of precession.
Analogies b
Rotational Energy
GOALS for this class:
* Examine principles and applications of rotational energy
storage.
* Apply rotational kinematics and Cons. of Energy to
situations involving rotational motion.
* Explore kinematics and Cons. of Energy with rolling
Torque
GOALS for this class:
* Identify and examine how to calculate torque as the
influence that controls rotational motion.
* Explore balance of torques as a condition for
rotational equilibrium.
* Relate torque to angular acceleration & rotational
iner
GOALS for this class:
* Explore applications of static equilibrium involving
balance of forces + balance of torques .
Static Equilibrium
For each body:
(1)
F 0
and
(2)
0
aboutany&
everyaxis
Choose torque axis or axes for convenience.
1
The torque produce
Simple Harmonic Motion Applications
GOALS for this class:
* Examine applications of Simple Harmonic Motion.
* Investigate approximations used to apply Simple
Harmonic Motion to a simple pendulum & elsewhere.
* Explore SHM dynamics of the physical pendulum