Spring 2015
Physics 172 Recitation 6
Circular Motion
Purpose: The purpose of this recitation is to give you some experience working with the
momentum principle in physical situations involving circular motion.
Readings: Chapter 5.1-5.5
Learning Objectives
Homework02-F15
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PHYS172-FALL15, Fall 2015
Instructor: Andrew Hirsch
Homework02-F15 (Homework)
Current Score : 19.75 / 25
Due : Thursday, August 27 2015 11:59 PM EDT
The du
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PHYS172-FALL15, Fall 2015
Instructor: Andrew Hirsch
Homework05-F15 (Homework)
Current Score : 19 / 21
Due : Saturday, September 5 2015 11:59 PM EDT
The due
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PHYS172-FALL15, Fall 2015
Instructor: Andrew Hirsch
WebAssign
Homework23-F15 (Homework)
Current Score : 15.41 / 16
Due : Tuesday, December 8 2015 11:59 PM
Final Exam
Place: MSEE B012
Date:
Thursday 8/5
Time: 8 10 am
Cumulative
Wont include Boltzmann
Bring your own equation sheet
1 piece of paper (8.5 x 11)
Boltzmann Distribution
psys
Fnet t
Esys W Q
Lsys , A net , A t
August 3, 2010
Chapter 12, Sections 7-
PHYS 172: Modern Mechanics
Lecture 25 - Kinetic theory of gases; pressure
Fall 2010
Read 12.8
Exam 3 Results
Machine-graded part: Average = 38.5/70
Hand-graded part:
Average = 17/30
Summary of Statistical Mechanics (Ch 12)
Counting states
S = kB ln
1
S
T
Fall 2013
Physics 172 Recitation 14
Entropy and Thermal Equilibrium
Purpose: The purpose of this recitation is to allow you to explore thermal equilibrium in
terms of distribution of quanta between microstates.
Readings: Sections 12.2-12.5
Learning Object
PHYS 172: Modern Mechanics
Lecture 23 Heat Capacity
Fall 2010
Read 12.6
Announcements
Exam 3 will be held on Thursday, Nov. 18, 8-10 pm in Elliott Hall.
Material through chapters 8, 9, 10, and 11 will be covered.
There will be a lecture on Nov. 18.
A prac
PHYS 172: Modern Mechanics
Spring 2012
Exam 3 multiple-choice part on CHIP
Please check your scores/answers on CHIP if
you see 0, let us know ASAP.
Finalizing iClicker scores 10-22
Scores for Lectures 10-22 have been uploaded. Deadline
for requesting corr
PHYS 172: Modern Mechanics
Spring 2012
Exam 3 averages
Multiple-choice: 67.7%
Hand-graded part: will be available next week
Finalizing iClicker scores 10-22
Scores for Lectures 10-22 have been uploaded. Deadline
for requesting corrections is 5 PM this Fri
Fall 2013
Recitation 13 Angular Momentum and Other Principles
Readings: Sections 11.1-11.6
Challenge Problem:
A playground ride consists of a disk of mass M and radius R mounted on a lowfriction, vertical axle. The ride is initially at rest. A child of ma
WW—
1. [5 points] [Exam #8]
For problems 1-4: Use the ﬁgures shown below:
A child with mass 30 kg rides on a merry-go-round, traveling at a constant speed |v|=l 11115. What is
the direction of Ap = pD - pA, the change in the child's momentum, between le
PHYS 172: Modern Mechanics
Spring 2012
Exam 3 averages
Multiple choice : 67.7%
Hand-graded part: 45%
Overall
: 60.7%
FINAL EXAM next Tuesday (May 1)
Comprehensive
20 multiple choice questions only.
Equation sheet will be posted later this week, please
PHYS 172: Modern Mechanics
Spring 2010
Final exam
Comprehensive
20 multiple choice questions only
Equation sheet: make your own, one double sided Letter size
Next (last) lecture: overview
Lecture 26 Maxwell-Boltzmann
Read 12.8
The Boltzmann distribution
N
IMPORTANT: Fill in the circle A after TEST FORM
under your signature on the answer sheet.
PHYS 172 Fall 2009
Tuesday, November 17th
EXAM 3 - TEST FORM A
There are two parts to Exam 1: the machine-graded part of this test, and the last page that
you turn i
Angular Momentum
Applications
July 22, 2010
Chapter 11, Section 9-10
Why Do Things Fall Over?
The center of mass can
apply a Torque
This starts a rotation
COM Torque is in
addition to all other
torques
The COM only applies a
Torque when it is not over a
s
172 Exam III Solutions - Summer 2008, J. Mattes
Q1: Answer = Choice 5.
Q2: Answer = Choice 3:
Angular momentum principle applied to system of just the grinding wheel:
Ltot,A = tot,A t gives that
|tot,A | =
Lrot
I
Ltot,A
=
=
=
t
t
t
1
2
2 M R |f
i |
(1)
t
PHYS 172: Modern Mechanics
Spring 2010
EXAM 2
Exam 2 multiple choice paper copies will be discarded tomorrow.
Any problem with Exam 2 scores should be addressed by Friday.
No complaints will be considered after that date.
Scores for 17 lectures are on CHI
PHYS 172: Modern Mechanics
,
Fall 2015
Lecture 23 Entropy & Temperature
Tuesday, Nov. 24
Chapter section 7.4:
introduced the idea that a systems internal thermal energy is the disorganized
microscopic internal kinetic and potential energy of the its atoms
PHYS 172: Modern Mechanics
Lecture 22 Entropy and Temperature
Summer 2012
Read 12.3 - 12.5
Clicker Question:
Consider the energy principle, Esystem=W+Q. Choose the correct
statement:
A. If Q is added to the system, the system temperature must increase.
B.
Phys 172H
Practice Exam
Fall 2007
1. Find the center of mass for the given disk that has two holes drilled (think of the
holes as the overlap of two disks, one of mass m and the other of mass m)
Assume that the disk has a uniform density and thickness.
y
PHYS 172 Summer 2008
Thursday, July 24
Exam 3
There are two parts to Exam 3: the machine-graded part of this test, and an inserted
portion that you turn in to be graded by hand.
Machine Answer Sheet:
Using a pencil, fill in Last Name, First Name, & Middle
Fall 2015
Physics 172 - Recitation 12
The Angular Momentum Principle
Readings: Sections 11.1-11.5
Challenge Problem:
A playground ride consists of a disk of mass M and radius R mounted on a lowfriction, vertical axle. The ride is initially at rest. A chil
Spring 2015
Physics 172 Recitation 3
Predicting Motion
The purpose of this recitation is to give you some experience using the update form of the
momentum principle and the position update formula to predict motion.
Readings: Chapter 2.3-2.5
Learning Obje
PHYS 172: Modern Mechanics
Lecture 11 The Energy Principle
CLICKER QUESTION
A) F1 and F2
B) F2 and F3
C) F3 and F4
D) F1 and F4
CLICKER QUESTION
A) positive
B) negative
C) zero
D) need more info
TODAY
Multiparticle Systems and Potential Energy
Relations
PHYS 172: Modern Mechanics
Lecture 8 Friction, Analytic Solution to Spring System
Summer 2015
Read 4.9 4.13
Contact Interactions: Normal Force
A brick is lying at rest on a metal table. Since it
remains at rest, we know the table must be
exerting a force
PHYS 172: Modern Mechanics
Lecture 15 Internal Energy
Summer 2015
7.1 7.10
Potential energy of a spring
y
Fs , x ks x
x
Us
U s
Fs , x
x
1
U s ks x 2
2
Potential energy of a spring:
1 2
ks s
2
1 2
U s ks s
2
Assume Us = 0 for relaxed spring
Real Life Phys
PHYS 172: Modern Mechanics
Lecture 17 Multiparticle Systems & Moment of Inertia
Summer 2015
9.1 9.3
Recall: Center of Mass
This is a weighted
average of the
positions - each
position appears in
proportion to its mass
where
Recall: Center of Mass
rcm
=
m1r
PHYS 172: Modern Mechanics
Lecture 7 Spring Model of Solids
Read 4.1-4.8
Spring Force
=
stretch
= 0
ks=spring constant in N/m
Contact Interactions & A Model of Solid Materials
An atom is a neutral system consisting of a positively charged nucleus and
a