AP Physics 2013-2014
Unit 8 - Rotation of a Rigid Body
Unit Objectives:
 Understand the uniform circular motion of a particle so you can:
 Relate the radius of a circle and the speed or rate of revolution of the particle to the magnitude of the centripetal
acceleration
 Describe the direction of the particle’s velocity and acceleration at any instant during the motion
 Determine the components of the velocity and acceleration vectors at any instant, and sketch or identify graphs of
these quantities
 Use the vector product and the right hand rule to:
 Calculate the torque of a specified force about an arbitrary origin
 Calculate the angular momentum vector for a moving particle
 Calculate the angular momentum vector for a rotating rigid body in simple cases where this vector lies parallel to the
angular velocity vector
 Understand angular momentum conservation so you can:
 Recognize the conditions under which the law of conservation is applicable and relate this law to one and two particle
systems such as satellite orbits
 State the relationship between net external torque and angular momentum, and identify situations in which angular
momentum is conserved
 Analyze problems in which the moment of inertia of a body is changed as it rotates freely about a fixed axis
 Analyze a collision between a moving particle and a rigid body that can rotate about a fixed axis or about its center of
mass
 Understand the concept of torque so you can:
 Calculate the magnitude and sense of the torque associated with a given force
 Calculate the torque on a rigid body due to gravity
 Be able to analyze problems in statics so you can:
 State the conditions for translational and rotational equilibrium of a rigid body
 Apply these conditions in analyzing the equilibrium of a rigid body under the combined influence of a number of
coplanar forces applied at different locations
 Develop a qualitative understanding of rotational inertia so you can:
 Determine by inspection which set of symmetrical bodies of equal mass has the greatest rotational inertia
 Determine by what factor a body’s rotational inertia changes if all its dimensions are increased by the same
factor
 Develop skill in computing rotational inertia so you can find the rotational inertia of:
 A collection of point masses lying in a plane about an axis perpendicular to the plane
 A thin rod of uniform density, about an arbitrary axis perpendicular to the rod
 A thin cylindrical shell about its axis, or a body that may be viewed as being made up of coaxial shells
 A solid sphere of uniform density about an axis through its center
 Understand the analogy between translational and rotational kinematics so you can write and apply relations among the
angular acceleration, angular velocity, and angular displacement of a body that rotates about a fixed axis with constant
angular acceleration
 Be able to use the right hand rule to associate an angular velocity vector with a rotating body
 Be able to state and apply the parallel-axis theorem
 Understand the dynamics of fixed axis rotation so you can:
 Describe in detail the analogy between fixed axis rotation and straight line translation
 Describe the angular acceleration with which a rigid body is accelerated about a fixed axis when subjected to a
specified external torque or force
 Apply conservation of energy to problems of fixed axis rotation
 Analyze problems involving strings and massive pulleys
 Understand the motion of a rigid body along a surface so you can:
 Write down, justify, and apply the relation between linear and angular velocity, or between linear and angular
acceleration, for a body of circular cross-section that rolls without slipping along a fixed plane, and determine the
velocity and acceleration of an arbitrary point on such a body
 Apply equations of translational and rotational motion simultaneously in analyzing rolling with slipping
Unit Outline
Date
M Jan 13
Day 4
W Jan 15
Day 1
Th Jan 16
Day 2
F Jan 17
Day 3
M Jan 20
No Classes
T Jan 21
Day 4
Th Jan 23
Day 1
F Jan 24
Day 2
M Jan 27
Day 3
Topic / Activity
Assignments
 Test Corrections
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 Angular position, velocity, acceleration (Chapter 9)
 Angular & Translational Quantities
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 Rotational Kinetic Energy
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~Science Drop~
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~Martin Luther King Day~
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Moment of Inertia
Parallel-Axis Theorem
Quiz: Angular position, velocity, acceleration
Problem Session
Torque (Chapter 10)
Newton’s 2nd Law
 Energy in Rotation
 Work-Energy Theorem
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T Jan 28
Day 4
Th Jan 30
Day 1
F Jan 31
Day 2
M Feb 3
Day 3
T Feb 4
Day 1
W Feb 5
Early Dismissal
Th Feb 6
Day 1
F Feb 7
Day 2
M Feb 10
Day 3
T Feb. 11
Day 4
Th Feb.13
Day 1
F-M Feb 14-17
T Feb. 18
Day 2
 Lab Packet: (Series of 3 labs)
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 Lab Packet: (Series of 3 labs) (Cont’d- if needed)
 AP Problems
 AP Problems
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~Science Drop~
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 AP Problems
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 MOI Challenge Lab
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 MOI Challenge Lab
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 Problem Session
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 Problem Session
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 Lab: TBD
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 Problem Session
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~Faculty Professional Development~
~President’s Day~
 Problem Session
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HW #24 (due Tue,1/21): pg.299-301
E: #1,3,5,8,9,11,13,15,16,18,21,22,
23,26,29
HW #25 (due Fri, 1/24): pg.301-2
E: #30,31,33,34,35,37,42,43,47,48
HW #26 (due Tue, 1/28): pg. 303
E: #53-57 (all)
HW #27: Handout (due Fri, 1/31)
HW #28 (due Tue, 2/4): pg. 334-6
P:#1,3,4,8,10,11,12,13,19,20,22,23,
29.31,33,35
HW #29 (due Tue., 2/11): pg. 303-6
P: #64,68,78,83,87,90
Extra Credit :# 95,100 (2 pts each)
pg. 338-40
P:#57,61,62,63,70,73,80,81
Complete Analysis Sheets
W Feb 19
Day 3
Th Feb.20
Day 4
M Feb. 24
Day 1
~Science Drop~
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 TEST: Rotation of a Rigid Body
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 Test Corrections
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Answers to even #’d problems (from book) are on Haiku…..